The limestone in this bay has gone through 500 million years of formation in different conditions and environments. The core of the bay has an area of 334 km 2 (129 sq mi) with a high density of 775 islets. Hạ Long Bay has an area of around 1,553 km 2 (600 sq mi), including 1,960–2,000 islets, most of which are limestone. These larger zones share a similar geological, geographical, geomorphological, climate, and cultural characters. Hạ Long Bay is a center of a larger zone that includes Bai Tu Long Bay to the northeast, and Cát Bà Island to the southwest.

The bay features thousands of limestone karsts and islets in various shapes and sizes. Administratively, the bay belongs to Hạ Long city, Cẩm Phả city, and is a part of Vân Đồn district. The name Hạ Long means 'descending dragon'. Hạ Long Bay or Halong Bay ( Vietnamese: Vịnh Hạ Long, IPA: i) is a UNESCO World Heritage Site and popular travel destination in Quảng Ninh province, Vietnam. Without proper rendering support, you may see question marks, boxes, or other symbols instead of chữ Nôm, chữ Hán and chữ Quốc ngữ.

Jungle island dragon city