Spa (Belgium): <i>Pouhon</i> (spring) Pierre-le-Grand, detail of the inside
Marc Ryckaert (<a href="//commons.wikimedia.org/wiki/User:MJJR" title="User:MJJR">MJJR</a>)
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>