Sweeney Ridge, is a 1,200-acre (5 km2) hilly hiking area of ridges and ravines between San Bruno and Pacifica, California, about a 25-minute drive south from San Francisco. The ridge's 1,200-foot-high summit, covered with coastal scrub and grassland, slopes down to San Francisco Bay on the east and to the Pacific Ocean on the west. The ridge is part of the Golden Gate National Recreation Area. Historically, the ridge is the location of the San Francisco Bay Discovery Site, commemorating the Portolá expedition's first sighting of San Francisco Bay on November 4, 1769 (expedition scouts actually made the discovery a few days earlier).