Chin Swee Tunnel (Malay: Terowong Chin Swee, Chinese: 振瑞隧道) is the longer of the two tunnels of the Central Expressway. It is located in the central part of Singapore, and starts after the exit 1B of Outram Road and in between , after the Outram Flyover. The tunnel passes through the junction of Chin Swee Road, , Upper Cross Street and , and later the junction of Clemenceau Avenue and . The tunnel later crosses the Singapore River and travels underneath Clemenceau Avenue, crossing River Valley Road. The tunnel then ends when it becomes a ground level expressway at the and Orchard Road exit. The tunnel passes through the site of the now demolished National Theatre building at River Valley Road.