Sarawak Chamber

In 1980, three British cavers, Andy Eavis, Dave Checkley and Tony White, explored Sarawak Chamber during the Mulu 1980 expedition. It was surveyed using traditional methods and it became apparent that it was then the world's largest known unsupported natural underground void.

 

In 2011, an expedition resurveyed Sarawak Chamber using a 3D Laser Scanner.

A total of 12.9 million points were measured using a MDL Quarryman LR laser scanner with an accuracy of 10-20cm

Sarawak Chamber has a volume of 9,579,205 m3 and an area of 164,459 m2. The maximum height is 115m and its extents are 600m x 435m.

In 2014 laser surveying in China revealed that Miaos Chamber in China is larger by volume at 10.78 million malthough Sarawak Chamber remains the world's largest by area. 

http://news.nationalgeographic.com/news/2014/09/140927-largest-cave-china-exploration-science/

Further information can be found at the Mulu Caves Project