Apo Reef, Philippines The Apo Reef in the Philippines is the largest contiguous reef after the Great Barrier Reef. It covers 67,877 acres off the coast of Mindoro Island and is surrounded by a mangrove forest. The reef was designated a national park in 1996, but environmental problems and overfishing severely taxed the reef. In … Continue reading Apo is a South Asian gem and breathtaking coral reef