The Giant Mirror in the Central Gallery of the Exploratorium at Pier 15.
<a href="//commons.wikimedia.org/w/index.php?title=User:ExploratoriumPI&amp;action=edit&amp;redlink=1" class="new" title="User:ExploratoriumPI (page does not exist)">the Exploratorium</a>
<span class="int-own-work" lang="en">Own work</span>