I had no idea this was here and I just adore Goldsworthy's work when I come across it. Great Highlight! I found this article about the history of the fallen tree line that explains why he created this piece, "More than a century ago, the U.S. Army began planting thousands of trees in San Francisco's Presidio as part of a massive forestation project, leaving a legacy of lush green space in the northern part of the city. Not all of the effort was successful, though; the cypress trees planted in the 1890s quickly died out, leaving gaps in a large eucalyptus grove -- gaps that a world-renowned British artist has filled with a new site-specific sculpture that came from the forest and will eventually return to it as well." http://www.treehugger.com/culture/artist-andy-goldsworthys-wood-line-follows-rich-history-of-san-franciscos-presidio-forest.html