King Fahd Causeway
The 26th longest tunnel in the world
The King Fahd Causeway (Jisr al-Malik Fahd) is a 25 km (15.5 mi) long series of bridges and causeways connecting Khobar, Saudi Arabia, and Al Jasra, Bahrain across the Gulf of Bahrain. Its five bridges rest on 536 concrete pylons, with seven embankments in the gulf's shallower water. One of the embankments, known as Middle Island (al-Jazirat al-Wustaa), has been converted into a sizeable artificial island with customs and immigration facilities, a mosque and gardens, and fast-food restaurants now known as Passport Island. Another island towards the eastern end of the causeway belongs to Bahrain and is known as Umm an Nasan (Um al-Na'saan). The causeway opened on 26 November 1986, making it the first bridge that connects an Island nation to its closest continent.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).