Fremantle Prison's Tunnels
You'll have to suit up for this subterranean prison adventure. Fremantle Prison's Tunnels Tour starts when you don a hard hat, overalls, tall rubber boots, and a headlamp, then climb down a 65-foot ladder. Still interested? You'll then crouch your way through passageways—some less than five feet high—while exploring the tunnels that have served as a water storage area for the prison since the late 19th century. Top it off by hopping a small boat and paddling your way through submerged tunnels. Tours run daily and last two and a half hours; book in advance.