The nearest cave temple to Kanchanaburi town is a spellbinding labyrinth of stone passageways. The marked trail can be slippery (and a bit of a squeeze) in places, but ducking beneath limestone protrusions to discover these subterranean shrines is an otherworldly experience; it's pin-drop silent (aside from fluttering bats) down here. The temple is 4km southwest of the town centre, beyond Chung Kai War Cemetery.
The chamber painted white near the exit was a Japanese wartime hospital. Outside, in a replica bamboo barracks, is a little display of POW photos. Follow the road to the back and you'll have a lovely view over Mae Nam Khwae Noi.