Apo Reef is the largest coral reef in the Philippines and a highly significant reef system that has a good, if small selection of scuba diving sites. The surrounding National Park consists of three tiny islands and two separate submerged coral reefs, which are divided by a channel.

Lying 33 kilometres west of the town of Sablayan on Mindoro, this isolated reef has it's benefits now that the surrounding waters are protected. For many years, Apo had attracted divers but destructive fishing discouraged marine tourism. When divers stopped coming altogether, the situation worsened. Conservation bodies are working in with the local government to have the area considered by UNESCO as a World Heritage Site.

Inside the park boundaries are coral reefs, seagrass beds and a shallow lagoon ringed by mangrove forests, which acts as a spawning ground and nursery for marine species as well as a sanctuary for birds.