(NPS photo by Neal Herbert)
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/100041491@N07">Natural Bridges National Monument</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/naturalbridgesnps/9474795694/">Prehistoric structures at Kachina Bridge</a>