it's known as the 'Blue Lagoon', but the flooded former quarry near Buxton hides a toxic secret.
It's so polluted that it's almost as toxic as bleach.
There are warning signs that state the water can cause skin and eye irritations and stomach problems, but people continue to swim there.
More top news
A number of people have been injured after a building collapsed in a suspected gas explosion in Wirral
Thirty-four people have been taken to hospital and two buildings have collapsed in an explosion thought to have been caused by a gas leak.
Dry, fine and sunny this weekend across the NW. Maybe a touch more cloud around and slightly breezier on Mothering Sunday than on Saturday