It is interesting how such a beautiful lighthouse ended up being interspersed through the prison buildings.  This tower was built around 1909 and was automated in 1963.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/9197427@N06">Pete Markham</a> from Loretto, USA
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/pmarkham/2348364169/">Alcatraz Island Lighthouse and Ruins</a>