The Bosphorus Tunnel is a major infrastructure project in Istanbul, Turkey, designed to connect the European and Asian sides of the city. Opened in 2016, it is a road tunnel that runs beneath the Bosphorus Strait, facilitating smoother traffic flow and reducing congestion on the bridges above. The tunnel is approximately 14.6 kilometers long and features advanced engineering to withstand seismic activity. It is part of a larger transportation network that includes highways and public transit, aiming to improve connectivity and support the growing population of Istanbul.