Situated in the province of Sorsogon is a volcano with 3,673 ha of mountain range and an elevation of 5,077 ft. This stratovolcano has 3 craters on the southeast edge; two of those are crater lakes. It is one of the four most active volcanoes in the country; the other three are Mt. Mayon in Naga, Mt. Taal in Talisay and Mt. Kanlaon in Negros Island.
On 2 August 2007, the volcano erupted, showering ash 5 km away on the villages. It was recorded that the volcano erupted 18 times since 1892.
Mt. Bulusan was declared as a national park by the national government in 1935 to protect and preserve its ecosystem. The park is covered by mossy forests and rain forest, natural springs, rivers and the mystical Bulusan lake that has an elevation of 2,084 ft. Mt. Bulusan serves as home to some of amazing rare species of flora and fauna.