It is formed on Lom Bo Island and seen from afar the entrance is like the roof of a house denting the island’s side. These chambers are somewhat small and narrow, but very refined and with many stalagmites and stalactites bearing beautiful forms.

Threading your way through narrow passages, you find a dim light from afar, which signals the exit of the grotto. On getting out of the grotto, climb up several rugged stone stairs and look down, you see a large round lake surrounded by the mountain. Its water is blue all year round. The lake is home to many kinds of fish, shrimps, octopuses, algae, see weed and coral. Lying adjacent to the lake there is an area of old trees popularly known as an alluring “royal garden”.

It is dry and well-ventilated, and features a thick layer of shells forming the foundation of the entrance. Formerly, this layer was 1.2-meter-thick and semi-fossilized. In the course of research, there was also a fossilized animal’s skeleton discovered in the interior.

Pushing into the grotto, visitors feel like walking in a palace of a Persian king. Hearing the murmur from out of nowhere, you think that Scheherazade is telling the stories of the Thousand and One Nights for her king. On the island, there are many ancient trees casting long reflections on the water of Halong bay. They are home to many species of birds and animals .