Halong Bay is one of Vietnam’s most popular tourist destinations, and its nickname as the world’s eighth wonder emphasizes just how unique an experience the area offers visitors. Halong Bay’s 1,969 limestone islands jutting from the ocean compose nearly 965 square miles and, contrary to local legend, were actually formed more than 500 million years ago.
The Bay itself is shaped like a triangle, formed by Dau Go Island, Ba Ham Lake, and Cong Tay Island. Most of the islands are between 150 and 650 feet high, while the smaller islets are only 15 to 30 feet tall. Some islands are hollow, containing hundreds of caves, many of which are archaeological sites. Of the nearly 1,000 caves given names, several take them from their appearance.