Upstream to the right of the crossing under the railroad tracks is the southern entrance to the Kerem Tunnel. The tunnel connects Nahal Refaim and Nahal Sorek. It was excavated as an infrastructure tunnel and was used for the Jerusalem sewer line to transfer sewage to the desalination plant in the lower stream of Nahal Sorek. In 2018, the tunnel became a bicycle tunnel and welcomed the first Jerusalem international bicycle ride. About six and a half thousand cyclists participated in this ride. As of September 2022, the tunnel is open for riding as part of the Jerusalem bicycle Trail. The tunnel is the fifth largest in the world for cycling.