Located in the southwest of Halong Bay, about 10 kilometers from Tuần Châu pier, Soi Sim Island is a tourist attraction for its pristine natural beauty. This island is also close to other prominent attractions such as Ti Top Island, Luon Cave, and Sung Sot Cave. On the island, there are numerous Sim trees - a type of bush bearing purple fruits, hence the local people named the island Soi Sim. Right at the foot of the island is a smooth white sand beach stretching about 200 meters, and in 2014, Soi Sim Island beach was recognized as a tourist beach.

Soi Sim Island covers an area of 8.7 hectares, entirely covered by a primary forest, home to many plant species, especially rare and valuable ones, typical of the Halong Bay ecosystem. Recently, a botanical conservation area is being developed on Soi Sim Island. The highlight of this project is the central exhibition house and the sightseeing area simulating a 9-petal flower. In the near future, this conservation area promises to create a new and attractive tourism product to attract tourists, contributing to the sustainable tourism development of the heritage region.