Tarantula Hill, is a 1,057-foot-high (322 m) peak in Thousand Oaks, California. It is located on a 45-acre (18 ha) open space and is operated by the Conejo Open Space Conservation Agency (COSCA). Climbing Tarantula Hill is a steep 0.5-mile (0.80 km) trail; the trailhead is located at 287 West Gainsborough Road, across the road from the main entrance to Conejo Valley Botanic Garden. Atop the mountain there is a 360-degree panoramic view of the Conejo Valley, the Simi Hills and the Santa Monica Mountains. There is also a fenced-in water reservoir located on top. It was once a popular hang-gliding site. It was once a volcanic mound but went dormant 16 million years ago.