Abismo Guy Collet
The Abismo Guy Collet (SP-090) is the deepest cave in South America, and the deepest in the world that is formed in quartzite. Located in a tepui in northern Brazil near the border with Venezuela, this cave was first explored by cavers in 2006 to a depth of 671 meters.
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.