Thomas Ladwig/San Diego Historical Center
Perched above Old Town and visible from many places in the city, this mission-style building is a notable landmark. Few seem to realize, however, that it’s also a museum. Founded by Franciscan monk Junípero Serra in the 18th century, the Presidio Park site was the very first European settlement in what is now known as California. Today, the tiny museum tells its history through drawings and artifacts. Outside, visitors can also enjoy hiking trails, lawns for picnicking, and sweeping views of downtown. There is no admission fee, but small donations are always welcome.