Near Pak Ou (mouth of the Ou river) the Tham Ting (lower cave) and the Tham Theung (upper cave) are caves overlooking the Mekong River, 25 km to the north of Luang Prabang, Laos. They are a group of two caves on the west side of the Mekong river, about two hours upstream from the centre of Luang Prabang, and have become well known by tourists.