Furong Cave

From Wiki China org cn

The Furong River Scenic Area has over 500 limestone caves, among which Furong Cave is the most renowned. Originally called the "Qi Cave," it is a giant elongated limestone cave, known as the "No. 1 Cave on Earth" for its extraordinary scientific and tourist value. It, together with the Mammoth Cave in the US and the Clamouse Cave in France, have been acclaimed as the three greatest caves of the world.