城門河
Tai Wai occupies the southwestern end of the Sha Tin Valley. The Sha Tin area is located directly northeast of Tai Wai. Hill ranges separate Tai Wai from New Kowloon in the south, and from Tsuen Wan in the west. The Tai Wai Nullah, sometimes referred to as the upper stream of Shing Mun River, flows through Tai Wai, where it joins the Shing Mun River. The Shing Mun River then flows in a southwest–northeast direction across the Sha Tin Valley towards Tolo Harbour.