Founded in 1889 and since abandoned, Wat Tham Xieng Maen is in a 100m-deep limestone cave called Tham Sakkarin Savannakuha (a little northwest of Wat Long Khun). Many Buddha images from temples that have been torched or otherwise fallen into decay are kept here; during Bun Pi Mai Lao many local worshippers come to Wat Tham to pay homage and cleanse the images.