Knapp's Castle is a privately-owned landmark ruined mansion in the Santa Ynez Mountains near Santa Barbara, California. Located near East Camino Cielo in the Los Padres National Forest, the ridge-top site has a panoramic view of Lake Cachuma and the Santa Ynez Valley. It is a popular destination for hikers and photographers.
George Owen Knapp, founder of Union Carbide, built Knapp's Castle shortly after purchasing the 160-acre (0.65 km2) parcel in 1916. In 1940, Frances Holden bought the property and invited her friend, world-famous opera singer Lotte Lehmann, to move in. The mansion was destroyed by a forest fire only five weeks later, and now only the massive sandstone foundations, fireplace pillars and walls of the original seven structures remain intact. The parcel is still privately owned but open to the public.
In January 2011, the site was undergoing new construction by the property owner, with a stone amphitheatre-style addition, some reinforcements, and other work. The county ordered a stop to the construction due to a lack of permits, but the construction equipment remains on site.
Coordinates: 34°31′24″N 119°47′35″W / 34.52333°N 119.79306°W