Upnor Castle
... that Upnor Castle in Kent only saw action once, in 1667, but failed to prevent one of the worst defeats ever suffered by the Royal Navy?
... that <b id="mwB9A"><a href="./Upnor_Castle" id="mwB9E" rel="mw:WikiLink" title="Upnor Castle">Upnor Castle</a></b> <i id="mwB9I">(pictured)</i> in <a href="./Kent" id="mwB9M" rel="mw:WikiLink" title="Kent">Kent</a> only saw action once, in 1667, but failed to prevent one of the worst defeats ever suffered by the <a href="./Royal_Navy" id="mwB9Q" rel="mw:WikiLink" title="Royal Navy">Royal Navy</a>?