It was discovered during an expedition by the Junglee Boss adventure tourism company.

The lake is located around one kilometre from the entrance of the cave, in one of the most pristine caverns in the area, situated deep within a strictly protected zone of the national park.

It was found in an area about 15 metres higher than the main underground river branch inside the cave, making it look like it was 'floating' on the cave wall.

The lake is surrounded by stalactite columns with an underground river system underneath it. The newly-discovered lake has a transparent emerald green colour.

The source of water flowing into the lake has not yet been determined, with the exploration team also discovering a passage along the cave wall of Thung Cave that traverses the main underground river branch.

Source: VNA