Hạ Long Bay, in northeast Vietnam, is known for its emerald waters and thousands of towering limestone islands topped by rainforests. Junk boat tours and sea kayak expeditions take visitors past islands named for their shapes, including Stone Dog and Teapot islets. The region is popular for scuba diving, rock climbing, and hiking, particularly in the mountainous Cát Bà National Park.
Erosion has created enclosed lakes such as Ba Ham Lake on Đầu Bê Island. There are also hundreds of caves, some with stalactites and 19th-century French graffiti. These include Đầu Gỗ Cave, the reported resting place of the bamboo stakes legendary military commander Tran Hung Dao used to repel 13th-century invaders. Most of the small islets are rocky and deserted but larger islands, such as Tuần Châu and Cát Bà, have settlements and beach resorts. Also typical of the bay are floating fishing villages such as Ba Hàng, where houses are built on wooden platforms.