Sometimes when you see the map, you find islands/peninsulas that are so close that there should be a bridge or tunnel connecting them. As technology advances, there are more and more mega-engineering projects built, under construction or being proposed. I will go through some significant and interesting ones here.

Connecting UK to France - Channel Tunnel

The first obvious one is of course the Channel Tunnel connecting UK to France and Europe. It is a rail tunnel over 50 km long carrying passenger trains (Eurostar), vehicle trains (Eurotunnel Shuttle) and freight trains. It was opened in 1994 and has the longest underwater section of any tunnel in the world.

Connecting Asia to Europe - Bosphorus Bridge

Bosphorus Bridge is the first of the three suspension bridges that span the Bosphorus Strait, connecting Asia to Europe in Istanbul. It has a main span of 1074 metres, making it the longest suspension bridge outside the United States when it was completed in 1973. Since then, the second bridge (Fatih Sultan Mehmet Bridge) was opened in 1988, and the third bridge (Yavuz Sultan Selim Bridge) was opened in 2016, alongside the Eurasia Tunnel (opened in 2016) and Marmaray (a commuter rail tunnel opened in 2019).

Bosphorus strait in Istanbul, separating Europe and Asia
Bosphorus Bridge

Connecting Sweden to Denmark - Øresund Bridge

The Øresund Bridge and the Drogden Tunnel connect Malmö in Sweden to Copenhagen in Denmark across the Øresund strait. It is a combined road-rail bridge. The bridge is 8 km long from the Swedish coast to an artificial island in the middle of the strait, and then another 4 km tunnel to Denmark. Constuction began in 1995 and it was opened to traffic in 2000.

Satellite image of Øresund strait and Øresund Bridge
Aerial photo of Øresund Bridge. Malmö is on top and Copenhagen Airport on bottom right.

Connecting Pearl River Delta - Hong Kong-Zhuhai-Macau Bridge

The concept of a road bridge/tunnel between Hong Kong and Macau was first proposed in the 1980s, connecting the British financial hub to the Portuguese gambling centre. The Hong Kong-Zhuhai-Macau Bridge (HZMB) was completed in 2018 and is the longest open-sea fixed link in the world, with a total length of 55 km. Although it is one country, Hong Kong, Macau and Mainland China each maintain their own immigration and custom. Two artificial islands were built, one on each side, for the border crossing facilities.

Connecting Faroe Islands - Eysturoy Tunnel

The Eysturoy Tunnel is a long undersea road tunnel (11 km) in the Faroe Islands connecting the island of Streymoy to the island of Eysturoy. It opened in December 2020 and is the largest infrastructure project ever in the Faroe Islands.

But what so cool about this tunnel is the world first undersea roundabout in the middle of its three-branch tunnel network. The roundabout is decorated with art sculpture and light effect.

Unfortunately I cannot find photo of the tunnel or roundabout in WikiCommons to post here, but you can google it or watch it on Youtube.

Map of the Eysturoy Tunnel, with a undersea roundabout at the Y junction

Connecting Dubrovnik to Croatia - Pelješac Bridge

The Pelješac Bridge was joined 2 weeks ago, connecting the Dubrovnik exclave with the rest of the country. It is expected to open to traffic in June 2022, so travelling on road to Dubrovnik from the rest of Croatia will no longer need to cross the border twice with Bosnia.

Construction of Pelješac Bridge
Location of the Pelješac Bridge

Connecting Sicily to mainland Italy? Strait of Messina Bridge 

The idea of a bridge connecting Sicily was there since the Romans time. The current plan of a single suspension bridge would have a central span of 3300 m, making it by far the longest suspension bridge in the world (by comparison, the central span of the Golden Gate Bridge is 1275 m).

It has been abandoned by the Italian parliament in 2006, but as recent as April this year, a private enterprise declared that they had €4 billion ready to build the bridge. So will we see this soon?

Strait of Messina
Cross-sectional diagram of the Strait of Messina Bridge

Connecting Morocco to Spain? Strait of Gibraltar crossing 

The Strait of Gibraltar crossing is a hypothetical bridge/tunnel connecting Morocco and Spain. The narrowest point is only 14 km apart, much shorter than the Channel Tunnel. Spain and Morocco started a joint feasibility study in 1979, and various proposals (bridge/tunnel) were put forward. However, the water is deeper than the English Channel, and it lies on an active major geological fault, making construction complex and costly (estimated to exceed €5 billion).

Strait of Gibraltar
You can literally see Africa (right) from Europe (left)

Connecting Sri Lanka to India? Palk Strait bridge

Sri Lanka was connected to India via Adam's Bridge until it broke in a cyclone in 1480.

India submitted a proposal of a 23-km Palk Strait Bridge to the Asian Development Bank in 2015. However, this was dismissed by Sri Lanka the same year. The bridge makes sense to me, so hopefully we will see this built some time in the future.

Satellite photo of Palk Strait and Adam's Bridge

Connecting Djibouti to Yemen? Bridge of the Horns

Bridge of the Horns is a proposed bridge across Bab-el-Mandeb connecting Djibouti to Yemen. The bridge will be 29 km long and estimated to cost US$20 billion. One of the uses is to provide East African Muslim easy access to the Hajj pilgrimage in Mecca. Original planning started in 2009, but with the civil war in Yemen since 2015, it is unlikely to get any further.

Bab-el-Mandeb between Red Sea and Gulf of Aden
Africa on the left and Asia on top right

Connecting Asia to America? Bering Strait crossing

This is probably one of the wildest ideas. But if Sarah Palin can see Russia from her house, then why not?

Eurasia–America Transport Link
Place of the potential bridge/tunnel via the Diomede Islands

Seriously, the Bering Strait crossing has been proposed as the missing link in building the intercontinental rail network. The longest single tunnel would be 40 km, which is shorter than the Channel Tunnel. However, to make this work, a lot of infrastructure are required especially in the remote Chukotka region on the Russian side, which is mostly roadless and uninhabited.

There are many other bridges/tunnels and ideas/proposals. If you are interested, let me know which one I should feature and I'll consider writing another blog. Thank you for reading.

Level 64
Aug 11, 2021
I've always hoped for the Bering Strait Crossing to be built so that people could be able to one day make a crazy journey from Europe to the United States, or even Cape Town to Punta Arenas. This is a great idea as well so great blog :)
Level 38
Aug 11, 2021
Amazing! Part 2 please!
Level 53
Aug 11, 2021
Awesome blog!
Level 65
Aug 11, 2021
Nice topic! Here are some of my crazy ideas (all of these are way too big, but would be cool if they were possible):

Australia to New Guinea

Java to Sumatra

Mindanao to Borneo

Greece to Turkey across the Aegean (you can go across Thrace but it would also be cool from Athens to Izmir)

Haiti to Cuba, or even crazier, Florida or Mexico to Cuba

Mozambique to Madagascar

Baku to Turkmenistan

Crimea to Northern Turkey

Tallinn to Helsinki

Taiwan to Luzon

Level 66
Aug 11, 2021
Great blog! I would love to see the Bridge of the Horns.
Level 57
Aug 11, 2021
Real cool, especially the one in the Faroe Islands, I hadn't heard of that before
Level 65
Aug 11, 2021
Neither did I, until I researched for this blog
Level 71
Aug 12, 2021
Great blog idea!
Level 54
Aug 13, 2021
Love it! waiting for next
Level 75
Aug 13, 2021
Great blog, very interesting and informative.

There is also proposals for a bridge / tunnel between Scotland and Northern Ireland.

Level 65
Aug 13, 2021
Thank you. Yes I heard about the Ireland bridge too. I'll include it if I get to write part 2.
Level 50
Aug 14, 2021
Very interesting and instructive blog! I like it.
Level 74
Sep 20, 2021
There's also the Sunda Strait Bridge.