With a total area of 242,967 hectares, the sanctuary is situated between the Sulu and Celebes Sea, straddling the Malaysia–Philippines border.

From the end of August to December, turtles come by the hundreds from the surrounding coastal waters, to lay and dig their eggs into the sand.

11038 (Expanded National Integrated Protected Areas System Act of 2018) signed by President Rodrigo Duterte in July 2018.

These include the vulnerable grey imperial pigeon (Ducula pickeringii), the near-threatened Mantanani scops owl (Otus mantananensis) and the Philippine megapode (Megapodius cumingii).

Additionally, there are limited areas of beach forest found on steep rock cliffs in Great Bakkungan and around the mud volcanoes in Lihiman.

Also, surrounding the active mud volcano on the northern section of Lihiman is a plantation of Casuarina equisetifolia.