Tags: Road Tunnel.
The Sarıyer-Çayırbaşı Tunnel (Turkish: Sarıyer-Çayırbaşı Tüneli) is a twin-tube road tunnel under the northern suburbs of Istanbul Turkey connecting Sarıyer district and Çayırbaşı neighborhood in the same district. The 4020 m (2.50 mi) long tunnel was opened in 2012.The tunnel is part of a project of the Istanbul Metropolitan Municipality to build seven tunnels for the City of Seven Hills which is the nickname of Istanbul.