Visitors to the Roman Baths this weekend had a bit of a shock when they spotted a lady in bright yellow who had decided to go for swim.
Dozens watched on as the woman swam around the green waters and even encouraged others to join her.
It's not known how long she was in the water for but she was eventually encouraged to climb back out.
Swimmers used to bathe once a year but in 1978, it was banned when a girl died from a strain of bacteria that was found in the waters.
Visitors who want to swim are now encouraged to visit the nearby Thermae Bath Spa which uses the same water but it's treated to make it safe.
Bath and North East Somerset Council has been approached for comment,