The Lassen Volcanic National Park is a unique and beautiful park located in Northern California. It is home to the largest plug dome volcano in the world, Lassen Peak, and is the only place in the world where all four types of volcano can be found. The park
From Wikipedia
Lassen Volcanic National Park is a national park of the United States in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcanoes can be found: plug dome, shield, cinder cone, and stratovolcano.