As of 2026-10-12, Tur‘at al Khadrāwīyah tops the list with 350 km.
- #1 Tur‘at al Khadrāwīyah — 350 km source Wikidata
- #2 Ar Rayyāḩ at Tawfīqī — 163 km
canal
source Wikidata - #3 Taiwan Strait Tunnel — 150 km
planned undersea rail tunnel
source Wikidata - #4 Japan–Korea Undersea Tunnel — 150 km
a proposed tunnel connecting Japan and Korea
source Wikidata - #5 Delaware Aqueduct — 137 km
aqueduct in New York State, U.S.
source Wikidata - #6 Päijänne Water Tunnel — 120 km
120-kilometre water tunnel in Southern Finland
source Wikidata - #7 Orange–Fish River Tunnel — 83 km
Irrigation tunnel in South Africa
source Wikidata - #8 Zarch Qanat — 80 km
qanat in Yazd County, Iranian national heritage site and World heritage site
source Wikidata - #9 Ishikawa Tunnel — 79 km
part of Japan National Route 329 in Uruma, Okinawa
source Wikidata - #10 Brenner Base Tunnel — 64 km
railway tunnel
source Wikidata