Ha Long Bay, situated in Vietnam’s Gulf of Tonkin, comprises over 1600 islands and limestone pillars, making it one of the most surreal places in the world. Geologically-savvy visitors can find an enormous array of caves, peaks and other landforms here. The bay is an extraordinary example of erosion’s effect on limestone. One of the most notable features is the well-developed notches, many of which extend into caves or arches. Because of the islands’ vertical natures, few are inhabited. While some are incredibly small, only 50 to 100 km high, the bay’s larger, more developed limestone islands contain their own lakes and other water sources. The name Ha Long Bay, from Chinese, means The Bay of Descending Dragons.