Established in the 8th century and one of the Konan Sanzan Trio of Tendai Buddhist National Treasure temples in Konan, Zensuiji's main Hondo Hall is a National Treasure. It is on the slope of Mt. Iwane.

Zensuiji means "Efficacious Water Temple." From JR Kosei Station on the JR Kusatsu Line, catch a bus and get off at Iwane 岩根. From there, you still have to walk a bit, follow the signs (if you can read Japanese). This road leads to one entrance to Zensuiji.