Presidio Spire by Andy Goldsworthy

This spire showed up last year on the Presidio with no explanation. Now there is an explanation: The Spire was made by Goldsworthy from trees felled from the 300 acre Presidio forest. (Trees planted by the army between 1886 and 1900 are being replaced 3 acres at a time to create an unevenly aged forest that will be easier to maintain)

"...as new young trees grow up to meet the sculpture, it will disappear into the forest."