Remarkable, ca 500 years old oak in Hersberg, <a href="https://en.wikipedia.org/wiki/Bech" class="extiw" title="en:Bech">Bech</a>, Luxembourg. Tree cavity with a statue of the Madonna. A pilgrimage site.
<a href="//commons.wikimedia.org/wiki/User:Cayambe" title="User:Cayambe">Cayambe</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>