Art and nature meet on this 3-mile hike through the Presidio. You can find 4 of Artist Andy Goldsworthy's installations during this hike the "Spire" stands near the Arguello gate in San Francisco's Presidio. Goldsworthy a world renown artist uses site-specific materials found in nature. For this particular installation, the artist used 37 felled Monterey cypress trees which he fastened together to make an impressive 100-foot tall "Spire". The installation, as well as some of the artist's other pieces (Earth Wall, Tree Fall, and Wood Line), can be accessed on a 3-mile hiking loop.