The last shift leaves <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Wearmouth_Colliery" id="mwARw" rel="mw:WikiLink" title="Wearmouth Colliery">Wearmouth Colliery</a> in <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Sunderland,_Tyne_and_Wear" id="mwAR0" rel="mw:WikiLink" title="Sunderland, Tyne and Wear">Sunderland</a>. The closure of the 156-year-old pit marks the end of the old <a href="https://en.wikipedia.org/wiki/County_Durham" id="mwAR4" rel="mw:WikiLink" title="County Durham">County Durham</a> <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Coalfield" id="mwAR8" rel="mw:WikiLink" title="Coalfield">coalfield</a>, which had been in operation since the Middle Ages.