Which reef is the Philippines' largest coral reef system?

The Philippines' largest coral reef system is Apo Reef.

Apo Reef lies off the western coast of Occidental Mindoro in the Mindoro Strait. Covering about 34 square kilometres, it is also regarded as the world's second-largest contiguous coral reef system. Most of the reef is submerged, while Apo Island, Apo Menor, and Cayos del Bajo mark parts of it above the surface.

The reef is protected as Apo Reef Natural Park, a marine protected area administered by the Philippines. It became a marine park in 1980, was declared a protected natural park in 1996, and received stronger national-park protection under the Expanded National Integrated Protected Areas System Act in 2018. Fishing inside the reef was banned in 2007 to aid recovery and conservation.

A common mix-up is Tubbataha Reef, another famous Philippine marine sanctuary and UNESCO World Heritage Site. Tubbataha is internationally celebrated for biodiversity, but Apo Reef is the country's largest coral reef system. Its lagoons, steep walls, mangroves, and clear water also make it a major diving destination.