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The answer depends on what counts as a bridge. The Hong Kong-Zhuhai-Macao Bridge is the largest overall sea-crossing system on this list at 55 kilometers, but that figure includes link roads, artificial islands, and a subsea tunnel. For the strict category of a continuous bridge over water, Guinness World Records recognizes the Lake Pontchartrain Causeway in Louisiana at 38.422 kilometers.
The 16 crossings below therefore use clearly labeled measurements: total system length, bridge length, water-spanning length, or shore-to-shore crossing distance. They include open-water bridges, estuary crossings, causeways, wetland viaducts, bridge-tunnel systems, and fixed links that combine several structures.
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At a glance: 16 exceptionally long water and wetland crossings
| Crossing | Headline measurement | What the measurement covers | Where to find it |
|---|---|---|---|
| Hong Kong-Zhuhai-Macao Bridge | 55 km overall; 29.6 km main bridge | Complete bridge-cum-tunnel sea-crossing system; main bridge stated separately | Pearl River Estuary, China |
| Lake Pontchartrain Causeway | 38.422 km / 23.87 mi | Continuous bridge over water; the longer southbound span | Metairie to Mandeville, Louisiana, United States |
| Hangzhou Bay Bridge | About 36 km | Overall bridge length across the bay | Jiaxing to Ningbo, Zhejiang, China |
| Manchac Swamp Bridge | About 36.7 km / 22.8 mi | Twin elevated highway structures through swamp and wetlands | I-55 near Manchac, Louisiana |
| Donghai Bridge | 32.5 km | Overall bridge linking Shanghai with Yangshan Port | Shanghai to Yangshan Island, China |
| Jiaozhou Bay Bridge | 26.7 km | Roadway bridge across the bay | Qingdao, Shandong, China |
| Atchafalaya Basin Bridge | About 29 km / 18 mi | Parallel I-10 bridges across the basin | Between Baton Rouge and Lafayette, Louisiana |
| Chesapeake Bay Bridge-Tunnel | 17.6 mi / 28.3 km shore to shore | Trestles, tunnels, bridges, islands, causeways, and approaches | Virginia Beach to Virginia’s Eastern Shore |
| Sultan Abdul Halim Muadzam Shah Bridge | 24 km overall; 16.9 km over water | Overall bridge and marine section | Batu Kawan to Batu Maung, Malaysia |
| Vasco da Gama Bridge | 17.2 km overall; about 12 km over water | Total bridge length and Tagus-spanning section | Lisbon, Portugal |
| Rio-Niterói Bridge | 13.29 km overall; 8.836 km over water | Total bridge length and Guanabara Bay section | Rio de Janeiro to Niterói, Brazil |
| Penang Bridge | 13.5 km overall; about 8.4 km over water | Total bridge length and marine section | Seberang Perai to Penang Island, Malaysia |
| Confederation Bridge | 12.9 km / 8 mi | Continuous bridge across ice-covered water | Prince Edward Island to New Brunswick, Canada |
| Seven Mile Bridge | 6.79 mi / about 10.93 km | Modern bridge across the Florida Keys waterway | Marathon to the Lower Keys, Florida |
| Øresund Bridge | 7,845 m | Bridge portion of a larger bridge-tunnel fixed link | Sweden to Peberholm, Denmark |
| Great Belt East Bridge | 6,790 m | Road suspension bridge portion of the fixed link | Zealand to Sprogø, Denmark |
China: major bay, estuary, and port crossings
1. Hong Kong-Zhuhai-Macao Bridge — Pearl River Estuary
Length: 55 km overall; 29.6 km for the main bridge.
#1 Best Overall
Find it: Across the Pearl River Estuary, connecting Hong Kong, Zhuhai, and Macao in southern China.
The Hong Kong-Zhuhai-Macao Bridge, or HZMB, is best described as the world’s longest bridge-cum-tunnel sea-crossing system—not simply as a 55-kilometer bridge. Its official breakdown is a 12-kilometer Hong Kong Link Road, a 29.6-kilometer Main Bridge, and a 13.4-kilometer Zhuhai Link Road. Together, those elements total 55 kilometers.
The system also includes a subsea tunnel and artificial islands. That makes its overall figure useful for understanding the scale of the complete crossing, while the 29.6-kilometer figure is the appropriate number when discussing the main bridge itself. [CIT-001][CIT-003]
2. Hangzhou Bay Bridge — Zhejiang
Length: About 36 km overall.
Find it: Across the mouth of Hangzhou Bay, between the Jiaxing and Ningbo areas of Zhejiang Province.
The Hangzhou Bay Bridge cuts across one of China’s broadest coastal waterways. Its commonly published length is approximately 36 kilometers, measured for the bridge crossing as a whole. It is often described as one of the world’s longest trans-oceanic bridges, although the exact category depends on whether a source is counting the bridge alone or a wider approach system.
For mapping purposes, “Hangzhou Bay Bridge between Jiaxing and Ningbo” is more useful than a country-only description. [CIT-004]
3. Donghai Bridge — Shanghai to Yangshan Deep-Water Port
Length: 32.5 km overall.
Find it: From mainland Shanghai to Yangshan Island and Yangshan Deep-Water Port.
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Donghai Bridge is an offshore port connection rather than a city-to-city landmark bridge. At 32.5 kilometers, it carries the transport link between mainland Shanghai and the deep-water port facilities at Yangshan. The location is therefore best searched as “Donghai Bridge, Shanghai, Yangshan Port.” [CIT-006]
4. Jiaozhou Bay Bridge — Qingdao
Length: 26.7 km for the bridge; approximately 41.58 km for the wider connection project.
Find it: Across Jiaozhou Bay in Qingdao, linking the city’s urban area with the Huangdao side of the bay.
The Jiaozhou Bay Bridge is frequently confused with the much longer Jiaozhou Bay Connection Project. The bridge itself is 26.7 kilometers long. The approximately 41.58-kilometer figure belongs to the broader connection project, which includes more than the bridge structure. Those numbers should not be substituted for one another.
Its setting is a large urban bay, so the bridge’s headline length describes the roadway crossing across Jiaozhou Bay rather than an uninterrupted open-sea deck. [CIT-007]
Rank #2
Louisiana and the wider United States: causeways, swamps, bays, and keys
5. Lake Pontchartrain Causeway — Louisiana
Length: 38.422 km / 23.87 mi.
Find it: Between Metairie, in the New Orleans area, and Mandeville on the north shore of Lake Pontchartrain.
The Lake Pontchartrain Causeway is the clearest entry for the strict category of a continuous bridge over water. Guinness World Records identifies the longer southbound bridge, completed in 1969, as the longest continuous bridge over water at 38.422 kilometers. [CIT-002]
That wording matters. The causeway is not necessarily the longest bridge when every type of bridge-tunnel system, approach road, or complete fixed crossing is included. It holds a more specific and more defensible record: a continuous bridge structure spanning water.
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Length: About 22.8 mi / 36.7 km.
Find it: Along I-55 near Manchac, Louisiana.
The Manchac Swamp Bridge is a pair of elevated concrete trestle structures carrying Interstate 55 through Louisiana’s swamp country. At approximately 22.8 miles, or 36.7 kilometers, it is one of the longest road crossings in the United States.
It is more accurate to call this a long water-and-wetland crossing than to imply that every meter passes over open water. The route crosses swamp, wetlands, channels, and flood-prone terrain—an important distinction when comparing it with a causeway across a lake or a bridge over a sea channel. [CIT-005]
7. Atchafalaya Basin Bridge — Louisiana
Length: About 18 mi / 29 km.
Find it: On I-10 between Baton Rouge and Lafayette, Louisiana.
The Atchafalaya Basin Bridge consists of parallel bridges carrying I-10 across the Atchafalaya Basin. Louisiana’s transportation department describes the crossing as approximately 18 miles long. It opened to traffic in March 1973 and remains a defining piece of the route between Baton Rouge and Lafayette.
Like the Manchac crossing, it demonstrates why “over-water bridge” can be a broad label. The basin is a river swamp made up of waterways, wetlands, and floodplain rather than one uninterrupted expanse of open water. [CIT-008]
8. Chesapeake Bay Bridge-Tunnel — Virginia
Length: 17.6 mi / 28.3 km shore to shore.
Find it: Across the lower Chesapeake Bay, between Virginia Beach and Virginia’s Eastern Shore.
The Chesapeake Bay Bridge-Tunnel is a complete shore-to-shore crossing, not a bridge-only structure. Its 17.6-mile length combines more than 12 miles of low-level trestles with two approximately one-mile tunnels, two bridges, artificial islands, causeways, and approaches.
That combination gives the crossing its name and its engineering character. The tunnels allow shipping channels to remain open, while the trestles and other structures carry the highway across the shallower portions of the bay. Its 28.3-kilometer figure should therefore be labeled “shore to shore” or “complete crossing,” not simply “bridge length.” [CIT-009]
9. Seven Mile Bridge — Florida
Length: 6.79 mi / about 10.93 km for the modern bridge.
Rank #3
Find it: Between Marathon and the Lower Keys along the Overseas Highway in the Florida Keys.
The modern Seven Mile Bridge is nearly 10.93 kilometers long. Despite its rounded name, its published modern-bridge measurement is 6.79 miles. It crosses the waterway between Marathon and the Lower Keys and is one of the most recognizable long bridge approaches in the United States.
This is a strong example of a bridge whose visual and travel significance exceeds its position in a strict length comparison. The exact figure also helps distinguish the modern bridge from the older parallel structure associated with the crossing. [CIT-015]
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10. Sultan Abdul Halim Muadzam Shah Bridge, or Penang Second Bridge
Length: 24 km overall; 16.9 km over water.
Find it: From Batu Kawan on the mainland to Batu Maung on Penang Island.
Known widely as Penang Second Bridge, the Sultan Abdul Halim Muadzam Shah Bridge has an overall length of 24 kilometers. Of that total, 16.9 kilometers is the marine bridge section over water. The distinction separates the full structure, including its approaches, from the portion actually crossing the surrounding waters.
It is important not to merge this bridge with the original Penang Bridge. They are separate crossings serving different routes between the mainland and Penang Island. [CIT-010]
11. Penang Bridge
Length: 13.5 km overall; about 8.4 km over water.
Find it: Between Seberang Perai on the Malay Peninsula and Gelugor on Penang Island.
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1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteThe original Penang Bridge was the first road connection between Penang Island and the mainland. Its total length is 13.5 kilometers, with approximately 8.4 kilometers over water. The shorter marine measurement is the useful one when comparing the bridge with other structures whose sources separately report water-spanning length.
For map searches, use “Penang Bridge” and the endpoints Seberang Perai and Gelugor. Do not confuse it with the 24-kilometer Penang Second Bridge. [CIT-013]
Europe: estuary and international fixed links
12. Vasco da Gama Bridge — Lisbon, Portugal
Length: 17.2 km overall; approximately 12 km over the Tagus.
Find it: Across the Tagus estuary in Lisbon, with the Lisbon-side landmark near Parque das Nações.
The Vasco da Gama Bridge crosses Lisbon’s broad Tagus estuary and was inaugurated in 1998. Its overall length is 17.2 kilometers, while approximately 12 kilometers spans the river and estuary waters. The total figure includes the complete bridge structure and its non-water portions, so both measurements are worth reporting.
Rank #4
“Vasco da Gama Bridge, Parque das Nações, Lisbon” is the most useful search description for readers trying to locate the structure, although the full crossing extends toward the northern bank. [CIT-011]
13. Øresund Bridge — Denmark and Sweden
Length: 7,845 m for the bridge portion.
Find it: From Lernacken near Malmö, Sweden, to the artificial island of Peberholm, Denmark.
The Øresund Bridge carries both motorway and railway traffic across part of the fixed link between Denmark and Sweden. Its bridge portion is 7,845 meters long. The complete Denmark-Sweden crossing continues through a tunnel from Peberholm to Amager near Copenhagen.
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Accordingly, 7,845 meters describes the bridge—not the entire Øresund Link. Calling the whole fixed link a bridge would overlook the tunnel and the artificial island that form part of the route. [CIT-016]
14. Great Belt East Bridge, or Østbroen — Denmark
Length: 6,790 m for the road suspension bridge portion.
Find it: Between Zealand and the small island of Sprogø, Denmark.
The Great Belt East Bridge is the road suspension-bridge section of Denmark’s Great Belt Fixed Link. Its length is 6,790 meters, spanning between Zealand and Sprogø. The wider fixed link also includes a railway tunnel and another bridge section, so the 6,790-meter figure belongs specifically to the East Bridge rather than to the complete crossing.
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This is another case where identifying the measured component prevents a misleading comparison between one bridge and an entire transport system. [CIT-017]
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15. Rio-Niterói Bridge — Brazil
Length: 13.29 km overall; approximately 8.836 km over water.
Find it: Across Guanabara Bay between Rio de Janeiro and Niterói.
Officially named the President Costa e Silva Bridge, the Rio-Niterói Bridge is the familiar name for this 13.29-kilometer crossing. Approximately 8.836 kilometers spans water in Guanabara Bay. A high central navigation span allows ships to enter and leave the bay, giving the bridge a prominent role in both road transport and maritime access.
When comparing it with other entries, use the 8.836-kilometer figure for the water-spanning section and the 13.29-kilometer figure for the complete bridge length. [CIT-012]
16. Confederation Bridge — Canada
Length: 12.9 km / 8 mi.
Find it: Across the Northumberland Strait between Borden-Carleton, Prince Edward Island, and Cape Jourimain, New Brunswick.
The Confederation Bridge is 12.9 kilometers long and crosses ice-covered water between Prince Edward Island and New Brunswick. Its defining superlative is not that it is the world’s longest bridge overall, but that it is recognized as the world’s longest bridge crossing ice-covered water.
Its endpoints are particularly useful for map planning: Borden-Carleton on Prince Edward Island and Cape Jourimain on the New Brunswick side. [CIT-014]
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A bridge’s published length can refer to several different things:
- Continuous bridge over water: the uninterrupted bridge structure itself, as with the Lake Pontchartrain Causeway.
- Overall bridge length: the full bridge from one end to the other, including sections over land, marsh, islands, or approaches.
- Water-spanning length: only the portion above a river, bay, estuary, sea, or other water body.
- Shore-to-shore crossing: the distance between land endpoints, which may include tunnels, causeways, artificial islands, and bridges.
- Complete transport system: a bridge-cum-tunnel or fixed-link route made up of multiple structures, as with the HZMB, Øresund Link, and Great Belt Fixed Link.
The surrounding environment matters too. Lake Pontchartrain and Hangzhou Bay are broad bodies of water; the Chesapeake crossing includes tunnels and artificial islands; the Louisiana crossings pass through swamp and floodplain; and the Confederation Bridge must contend with ice-covered water. Treating all of those settings as identical would make the numbers look more precise than they really are.
What is the longest over-water bridge?
For a continuous bridge deck over water, the Lake Pontchartrain Causeway is the clearest answer at 38.422 kilometers. That is the Guinness World Records category: “longest bridge over water (continuous).”
For the largest complete sea-crossing system in this list, the answer is the Hong Kong-Zhuhai-Macao Bridge at 55 kilometers. However, its total includes 29.6 kilometers of main bridge, link roads, artificial islands, and a subsea tunnel. It should not be described without that qualification.
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1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteThere is no single meaningful descending ranking for all 16 crossings unless the measurement rules are standardized first.
A note for readers planning a visit
This is a reference list rather than a current travel-access guide. Tolls, traffic rules, permitted stopping points, viewpoints, public access, and photography restrictions can change, so check the relevant bridge operator, transportation authority, or destination authority immediately before traveling. The map-friendly endpoints above identify where each crossing is located without making unsupported claims about visitor facilities or access.
Measurement note: Figures follow the supplied source set, including Guinness World Records and official or government bridge and transportation descriptions. Because source conventions differ, each entry identifies whether its number refers to a complete system, bridge, water section, or shore-to-shore crossing. [CIT-001][CIT-002]
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Which is the world’s longest bridge over water?
The Lake Pontchartrain Causeway in Louisiana is the clearest answer for the specific category of longest continuous bridge over water: 38.422 kilometers, or 23.87 miles. Guinness World Records applies that record to the longer southbound span.
Is the Hong Kong-Zhuhai-Macao Bridge 55 kilometers long?
The complete Hong Kong-Zhuhai-Macao sea-crossing system is officially described as 55 kilometers long. That total includes the 29.6-kilometer main bridge, link roads, artificial islands, and a subsea tunnel. It is more accurate to call it a 55-kilometer bridge-cum-tunnel system than a 55-kilometer bridge.
Are all 16 crossings entirely over open water?
No. The list includes bridges over bays, estuaries, lakes, straits, and coastal waters, but also wetland crossings, causeways, artificial islands, tunnels, and land-based approaches. Each length is labeled to show what it measures.
What is the difference between Penang Bridge and Penang Second Bridge?
They are separate Malaysian crossings. Penang Bridge is 13.5 kilometers overall, with about 8.4 kilometers over water. Penang Second Bridge, officially the Sultan Abdul Halim Muadzam Shah Bridge, is 24 kilometers overall, with 16.9 kilometers over water.
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There are two defensible headline answers: the Hong Kong-Zhuhai-Macao Bridge is the largest complete sea-crossing system here at 55 kilometers, while Louisiana’s Lake Pontchartrain Causeway is the longest continuous bridge over water at 38.422 kilometers. The remaining crossings become comparable only after distinguishing bridge deck, water section, approach, tunnel, wetland, and shore-to-shore measurements.
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