Arrange with the boatman to visit the Bat Cave and the waterfalls. Be prepared for an energetic half-day's activity. The boat will let you off on the far side of the dam where you have to follow a beaten track around the other side of the mountain and two-thirds of the way up. It's a marvelous hour's trekking and nothing like a standard tour. You are unlikely to encounter another soul either on the jungle path or at the cave or waterfall. It's just you and nature… and the bats.