The Monterey State Historical Park is a collection of historic buildings from the early 19th century. The Pacific House, which was built in 1847 as an army headquarters, is now a museum. Their exhibits explain the local history when Spain and then Mexico ruled Alta California before it was liberated at the end of the Mexican-American War. The museum also tells the story of the indigenous Indians who lived here for thousands of years before the first Spanish explorers arrived in 1542.