Nguom Ngao means “tiger’s cave” in the language of the local Tay ethnic minority. It is said that a long time ago, many fierce tigers sheltered in the cave and would enter the nearby village to hunt for livestock and even humans.

The main entrance to this cave is some 2km from Ban Gioc Waterfalls, just off the road to Cao Bang. Wonderful beauty of Nguom Ngao spreads the cavern. A British study in 1995 found the grotto to be 2,144 meters long, reaching heights of up to 60 m, with three main entrances namely Nguom Ngao, Nguom Lom and Ban Thuon.

The stone with the shape of a lotus bud turning up side down

At its main entrance, you can feel the fresh, cool air from the natural mist inside. Nature has endowed the cave with stone formations that look like human beings, trees, plants and mythical animals.

The cave was formed due to weathered process of limestone mountains by wind and water over a long time. Stepping in the cavern, you seem to see a miraculous world. From high stone cliffs, hanging wonderful sparkling seven-colored stalactites. Along the way are stalactites of all shapes that look like boats, cactus, forests, terraced rice fields - a symbol of mountainous region of Vietnam and poles and valleys that are said to create a link between the earth and the heaven and a loving tie between men and women.

The cave is enormous (about 3km long) and one branch reaches almost all the way to the waterfalls, where there is a ''secret'' entrance. Nguom Ngao has been recognized as a national relic. Without doubt, Nguom Ngao Cave and Ban Gioc Waterfalls are two must-see natural wonders in the northern province of Cao Bang.