Harpur Hill Quarry
... that High Peak Borough Council dyed a lake black at Harpur Hill Quarry in Derbyshire, England, to deter swimmers from entering the caustic waters?
... that <a href="./High_Peak_Borough_Council" id="mw-w" rel="mw:WikiLink" title="High Peak Borough Council">High Peak Borough Council</a> dyed a lake black at <b id="mw_A"><a href="./Harpur_Hill_Quarry" id="mw_Q" rel="mw:WikiLink" title="Harpur Hill Quarry">Harpur Hill Quarry</a></b> in <a href="./Derbyshire" id="mw_g" rel="mw:WikiLink" title="Derbyshire">Derbyshire</a>, England, to deter swimmers from entering the caustic waters?