Pinnacles National Monument is a protected mountainous area located east of central California's Salinas Valley. The Monument's namesakes are the eroded leftovers of half of an extinct volcano.The Monument is divided by the rock formations into East and West Divisions, connected by foot trails; there is no through road that connects the east end west entrances to the park. The east side has shade and water, the west has high walls. The rock formations provide for spectacular pinnacles that attract rock climbers. It is popular with advanced rock climbers due to the many difficult and challenging climbs. The Monument is most often visited in spring or fall because of the intense heat during the summer months.