In 2013 Scotland’s largest producer of coal, Scottish Coal, unexpectedly went into liquidation leaving many open cast coal mines in a dangerous and unmaintained condition. The legally required restoration bonds were over £200 million short of the amount necessary to restore the mines. Several sites are slowly being returned to a satisfactory condition, but most have been left as a hazardous scar on the landscape. The huge pits slowly fill up with toxic water which leaches into underground aquifers, threatening local drinking water quality, sheer sides make escape impossible if someone is unfortunate enough to fall in, ex workers talk of heavy machinery and large quantities of enormous tyres deliberately disposed of in flooded excavations.