Lassen Volcanic National Park, California
The word "volcanic" suggests something hot, active, impetuous. In terms of human traffic, Lassen Volcanic National Park in the southern Cascade range is pretty sleepy. But don't be fooled. Just because the park is less visited than other parks in California doesn't mean it's a snoozefest. In fact, it's quite the opposite. Filled with boiling mud pots, steam-spewing fumaroles and a decidedly mercurial volcano, Lassen Peak, this park is a real treat for those who like their terrain unsettled, their weather unpredictable and their trails to be called "Bumpass Hell."