Walpole Park's eastern ornamental pond. Original purpose may have been Pitzhanger Manor's garden's  ha-ha against cattle and sheep.
<a href="//commons.wikimedia.org/wiki/User:P.g.champion" title="User:P.g.champion">P.g.champion</a>
CC BY 2.0 uk
<span class="int-own-work" lang="en">Own work</span>