Sydney Kingsford Smith Airport, Australia

A unique structure built directly under the runway. Constructed in the early 2000s as part of the M5 East motorway, it connects urban highways to the airport area without interfering with aircraft movements above. The tunnel stretches about 600 meters, passing under an active runway where planes take off and land every few minutes.

Fun Fact: This tunnel is one of the few in the world built directly under an active airport runway, showcasing innovative engineering to merge road and air traffic seamlessly. 🛫🚗