Tham Lod Cave, on the way to Mae Hong Son via Pai. Thai 20 baht, Farang 200 baht collected by staff dressed in military camouflage gear. Plus 200 baht for a local Thai guide who knew nothing. Apart from the creek that flows through it, (you can raft through during the dry season) the cave is black, dry and dirty and the smell of bat poo is overwhelming. Wear a mask or give it a miss.