There are some famous caves in Halong Bay such as Sung Sot (Amazing Cave), Luon (Tunnel Cave), and Thien Cung (Heaven Palace Cave) which are very beautiful but quite crowded with tourists recently. If you go just a little further, to a more quiet area, you will find an extremely special cave where limestone mountains meet the sea creating a unique combination of nature, Bright Cave. Bright Cave lies on the border of Halong Bay, Bai Tu Long Bay, and Lan Ha Bay, near Cat Ba National Park. Formed by an enclosed group of islets, this cave connects with the sea via a 4-meter-wide, 100-meter-long, and 3-meter-high mouth.

A bamboo boat ride to Bright cave is an amazing experience on Lan Ha Bay overnight cruise, offered by Perla Dawn Sails. Bright Cave is an incredible piece of this World Heritage site and is said to be one of the best places to go to for kayaking, swimming or photography. In a Lan Ha Bay overnight cruise on Perla Dawn Sails, you will enjoy a special trip on a locally operated bamboo boat cruising to Bright Cave, where you will enter an angled passageway tothe cave at the water level. Besides the lovely passage is a serene round lake encompassed by lush trees and very high, natural stone walls resembling a stadium surrounded by a high platform.

Going around the lake, you might imagine being in a colorful garden with the Benjamin fig trees and various sweet-scented orchids spreading their blooms, close enough to be touched. The pristine water is a habitat for many species of prawns, fish, crab, and cuttlefish. On the cliffs,  one still discovers hints of fossilized freshwater snails, demonstrating that humans have used these natural surroundings for many, many years.