The Blue Lagoon near Buxton, a flooded quarry - has inviting turquoise waters, but it is so polluted it's almost as toxic as bleach.
There are warning signs saying it can cause skin and eye irritations and stomach problems, but families and young swimmers are ignoring them.
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Some showers at first this evening, gradually clearing overnight. Tomorrow, a mostly dry day but with a few showers.
A good deal of cloud this evening and overnight, with showery outbreaks. Tomorrow, generally cloudy, with some sunny intervals.
A transgender teen from Gloucester has told ITV News how he plans to freeze his eggs before his sex change in order to have children.