Bubbling mud pots, boiling pools of water and steaming fumaroles bear witness to the ongoing tumult beneath the Earth's surface at Lassen Volcanic National Park. The park's peaks and formations include four separate types of volcano: shield, plug dome, cinder cone and composite remnants. 150 miles of hiking trails provide ample sightseeing opportunities up to peaks and around mountain lakes, while the Main Park Road offers access to hydrothermal areas such as Devils Kitchen and Bumpass Hell.