Ha Long Bay, a UNESCO heritage site, in the Gulf of Tonkin, includes some 1,600 islands and islets, forming a spectacular seascape of limestone pillars. Because of their precipitous nature, most of the islands are uninhabited and unaffected by a human presence. The site’s outstanding scenic beauty is complemented by its great biological interest. A cruise trip for 2 or 3 days is basically needed to explore and admire Halong bay natural landscape’s magnificent view.