The Gulf of Tonkin is a saltwater bay in between Vietnam and China, a north-west section of the East Sea and part of the Pacific Ocean, covering an area of approximately 126km². The Bay has two gates to the ocean; the main gate is in the area of Con Co Island in Quang Tri Province, Vietnam while the other is situated in China.
The Gulf is comprised of three bays, Halong bay, Bai Tu Long Bay and Lan Ha Bay. The area characterised by thousands of limestone islands, formed by millions of years of erosion and tectonic processes creating breathtaking scenery, with beautiful caves and spectacular seascapes. Its aesthetic and geological value was recognised when Halong Bay, a part of the Gulf of Tonkin, was listed as a UNESCO World Heritage Site.
A limited area of the Gulf is open for public visit. Many areas still remain untouched, their hidden charm waiting to be explored.