Tham Sakkalin

Ask at the Wat Longkhun ticket desk for the key required to visit Tham Sakkalin, a humid, slippery 100m-long limestone cave. It's a three-minute walk further east from the wat then up a few stairs. A few Buddha fragments are kept here. Bring your own torch (flashlight). Inside the cave is Wat Tham Xieng Maen, founded in 1889 and since abandoned.