Hidden among the thousands of jungle-covered peaks rising dramatically out of the emerald waters of Halong Bay are illuminated caves, isolated grottos and picturesque hidden coves of all shapes and sizes. Hop on board a row boat and venture out to explore these hidden gems for yourself, such as the beautiful Thien Cung Cave – nicknamed the Heavenly Palace Cave, famed for its many stalagmites and stalactites, and Dau Go Cave – known as the Cave of Wonders, featuring fascinating rock formations illuminated by a kaleidoscope of colour.