Pak Ou caves, also known as Tham Ting and Tham Theung, are a group of natural caves located near the Mekong River in northern Laos. The caves are known for their collection of thousands of Buddha statues, which have been left behind by pilgrims and visitors over the centuries.

There are two main caves at Pak Ou: Tham Ting and Tham Theung. Tham Ting is the lower cave and is easily accessible by boat or road. It contains hundreds of small and large Buddha statues of various sizes and materials, including wood, stone, and bronze. Tham Theung is the upper cave, which requires a short climb up a steep set of stairs. It is less accessible but is home to a smaller number of larger and more ornate Buddha statues.

The caves are believed to have been used for Buddhist worship since the 16th century, when the Lao kings and local people began placing Buddha statues in the caves. Today, the caves are a popular pilgrimage site for both domestic and international visitors, particularly during the Lao New Year in April.

Visitors to Pak Ou caves can explore the caves and marvel at the thousands of Buddha statues, many of which are centuries old. The caves are also set against a beautiful natural backdrop, with the Mekong River and surrounding limestone cliffs providing a stunning view.

Pak Ou caves are located about 25 kilometers north of the ancient city of Luang Prabang, and can be reached by boat or road. There are several tour companies that offer guided tours to the caves, which typically include a stop at a nearby village and a traditional Lao lunch.