Encompassing 34 km2 (13 sq mi), it is considered the world's second-largest contiguous coral reef system, and is the largest in the country.

[3] Politically, the reef lies within the jurisdiction of the Province of Occidental Mindoro in Region IV-B of the Philippines and, more specifically, of the Municipality of Sablayan.

The park has been designated an Important Bird Area (IBA) by BirdLife International because it supports a significant seabird population, with at least 10,000 breeding pairs recorded.

It is 34 km2 (13 sq mi) of almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west.

The Apo Reef Light, situated on the north-east part of the island, warns ship about the location of this navigational hazard.

[6] Cayos del Bajo are flat coralline rock formations with no vegetation on the northern lagoon near the eastern edge of the reef.

[1] Following a survey by the local chapter of the World Wide Fund for Nature, fishing within the reef was banned by the Philippine government in September 2007.

[11][12] The marine park opened for tourists to help generate funds for its protection as well as provide an alternative livelihood for hundreds of fishermen in the area.

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

Scuba diving and snorkeling in Apo Reef area are exceptional due to the quality of the flora, the fauna and the clarity of the water and white sand.