Iraya is a stratovolcano rising 1,009 meters with a base diameter of 5,500 meters. Its adjacent volcanic edifices are Mt. Matarem and Mt. Mahatao.
Iraya is a dormant volcano that last erupted in 1454.
But in 1998, volcanolgists recorded a seismic swarm which led them to form a monitoring network on Batan Island for several months.
It is one of the 22 active volcanoes in the Philippines: Babuyan Claro, Banahaw, Biliran, Bud Dajo, Mount Bulusan, Cagua, Camiguin de Babuyanes, Didicas, Hibok-Hibok, Mount Iriga, Mount Kanlaon, Leonard Kniaseff, Makaturing, Matutum, Mayon, Musuan, Mount Parker (Cotabato), Pinatubo, Ragang, Smith Volcano, Taal. They are all part of the so-called "Pacific ring of fire."
Mt. Iraya, can be climbed, but only during the height of the dry season and with the aid of a guide. The usual way starts at Basco. There are no clear trails through the dense rain forests that cover the slopes. For those who prefer not to climb to the peak, there are trails that lead part of the way up the slope and then around the volcano to its coastal side.
- Philippine Institute of Volcanology and Seismology (PHIVOLCS) Iraya Page
- Smithsonian Institution's Global Volcanism Program