<a href="https://en.wikipedia.org/wiki/Key_West_Historic_District" class="extiw" title="en:Key West Historic District">Key West Historic District</a>, the Fresnel lens at the Key West Lighthouse Museum, Florida, USA
<a href="//commons.wikimedia.org/wiki/User:Acroterion" title="User:Acroterion">Acroterion</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>