This football-stadium-sized cave is simply breathtaking, its entrance dominated by dozens of buddha statues, a couple of pagodas and some newer clay wall carvings.
With the cave now illuminated, you can scramble for 15 or 20 minutes through chambers as high as a cathedral, past truck-sized stalactites and, in places, walls of crystal.
Adding to the general atmosphere, thousands of bats cling to the cave roof. Their squealing is deafening in places – watch out for bat excrement.
As you emerge at the cave’s far side the wonders only increase: the burst of sunlight reveals a secret lake full of ducks and flowering lilies hidden in a bowl of craggy peaks. There's another cave on the far side of the lake that's actually half flooded, but local fishers occasionally paddle through it for 10 minutes to yet another lake. You may be able to persuade someone to take you along.
Saddan Cave can be traversed only partially during the rainy season. Come during the dry season (around November to April) for the full experience. The cave is 17 miles from Hpa-an along the road to Eindu. To get here, take a pick-up to Eindu; from Eindu take a motorbike taxi (K3000) for the remaining few miles to the cave.