different stones, surface covered with cauliflower-like lime-crust, in german - "Krustensteine", locality: <a href="https://en.wikipedia.org/wiki/de:Chiemsee" class="extiw" title="w:de:Chiemsee">w:de:Chiemsee</a>, <a href="https://en.wikipedia.org/wiki/de:Bayern" class="extiw" title="w:de:Bayern">w:de:Bayern</a>
Hans Lauterbach <a href="//commons.wikimedia.org/wiki/User:Furchenstein" title="User:Furchenstein">Furchenstein</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>