From a distance, an abandoned quarry at Harpur Hill in the English town of Buxton looks like a true paradise. The water is a brilliant turquoise blue that looks like something from the Mediterranean. Locals call it the “Blue Lagoon”. But looks can be deceiving. In reality, the water in the pool is blue due to chemical pollution – toxic leftovers from its industrial days. There are signs close to the shoreline that warn people of the pool’s dangerous contents that include abandoned cars, dead animals and human waste, and the ‘beach’ is limestone chippings. Despite the warnings, the flooded quarry had become a bizarre holiday destination as young people and even families turn up to camp out, swim and hold all-night drinking parties there because the web pictures show an idyllic stretch of water with a ‘beach.’

The attractive coloring of the water is caused by the surrounding limestone rocks which leach calcite crystals into the water, turning it turquoise. The calcium oxide in the water turns it alkaline with a pH level of 11.3, only slightly lower than bleach (ph 12.6) and ammonia (pH 11.5) - toxic enough to cause skin and eye irritations, stomach problems and fungal infections.

In June 2013, the council poured black dye into the water to lessen its appeal, and so far the plans has worked. Tourists have stopped swimming in it. Local business owner Rachel Thomas told to BBC, “They don't think they're on holiday in the Bahamas any more, they know they're in Harpur Hill.”