pile bridges
...hammered oak piles used during the Medieval construction of pile bridges have remained solid for up to 750 years?
...hammered <a href="./Oak" id="mwDW8" rel="mw:WikiLink" title="Oak">oak</a> piles used during the <a class="mw-redirect" href="./Medieval" id="mwDXA" rel="mw:WikiLink" title="Medieval">Medieval</a> construction of  <b id="mwDXE"><a href="./Pile_bridge" id="mwDXI" rel="mw:WikiLink" title="Pile bridge">pile bridges</a></b> have remained solid for up to 750 years?