Rests of ice in the Havel river at the Ernst-Liesegang-Ufer in Berlin-Kladow- You should hear the sound when waves were coming.
<a href="//commons.wikimedia.org/wiki/User:Southgeist" title="User:Southgeist">Dirk Ingo Franke</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>