Near Broken River Bridge, 2km northeast of Castle Hill, a car park signals access to this 594m-long cave. As indicated by the information panels, the walk through it is an achievable adventure, even for beginners, but only with a foolproof torch and warm clothing, and definitely only if the water level is less than waist-deep where indicated. Heed all notices, take necessary precautions and revel in the spookiness. Failing that, just wander around the 10-minute loop track for a gander at the surrounds.