Annual holiday tree in front of the historic military hospital in San Francisco's Presidio.
The Presidio tree lighting in 2008 is unique in that attendees have a chance to “light the tree.” From the Presidio Trust press release:
“We all join hands in a large circle,” explains Hilstrom. “The 'electricity’ is passed around the circle by everyone squeezing the hand of the person next to them. When the circle is completed the tree magically lights up."
Related:

