Dike between Vistula river (right side) and Ptasi Raj lake (left side). <a href="//commons.wikimedia.org/wiki/Gda%C5%84sk" title="Gdańsk">Gdańsk</a>.
<a href="//commons.wikimedia.org/wiki/User:Panek" title="User:Panek">Panek</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>