Tlacolula de Matamoros
The caves and rock shelters vary in size and what they contain. Many contain paintings and other forms of graphic representation. Contents include ceramics and stone tools. The corn materials show similarities to the first vestiges of the domestication of wheat and rye in the Middle East. One of the deepest caves is called the Cueva de la Paloma. The caves have been studied since the 1960s, especially the Cueva de Guilá Naquitz (white stone in Zapotec), which has some of the best evidence for the domestication of corn and squash, which dates back more than 10,000 years. Other caves, such as those near Yagual and Mitla confirm findings at Guilá Naquitz and show human occupation to about 8000 years BCE the sites also show similarities to the Head Smashed and Buffalo Jump Complex sites in Canada. Many more smaller caves with similar artifacts are thought to exist in the area.
Oudomxay Province
Chom Ong Cave, the longest cave in Laos, is located in Ban Chom Ong, 45 km to the northwest of Oudomxay town and is the biggest known cave in northern Laos. The cave was explored by a team of cave researchers during 2009, 2010 and 2011 and reported to be 18.4 km long and considered as the second longest in Laos and 9th longest in South East Asia. The average dimensions of the cave is 20–25 m in width and 20–30 m in height. It has two passages, one is a stream and the other has fossils and both connect to a large hall which is 100 m long, 30 m wide and of varying height of 30–50 m up to the roof. It has a stream inlet in the north and the stream outflows in the southern end.