Monterey State Historic Park is a collection of significant historic houses and buildings interspersed throughout Old Monterey. The inside of the Stevenson House, Larkin House, Cooper-Molera Adobe, and Casa Soberanes can ONLY be viewed with a State Park Guide. These four guided house tours, the Guided Walking Tour of Old Monterey, the Pacific House Museum and Custom House are all FREE. Guided Walking Tours begin at the Pacific House Museum in Custom House Plaza – a great way to start your discovery of Monterey.