People are being warned against swimming in a former quarry full of chemicals.
It's known as the 'Blue Lagoon' and it's tranquil turquoise waters draw people from far and wide.
But experts say it's PH levels make it almost as toxic as bleach.
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Remaining largely cloudy with patchy drizzle over hills. Becoming milder, breezy with some brighter breaks in the west on Friday
Saturday looks like the best day of the weekend. Mainly dry for both Saturday and Sunday but a cooler, cloudier finish
Another largely cloudy and murky day. Perhaps a little brighter and feeling milder for Friday