The Barton Square Mall in Manchester has an aquarium called Sea Life Manchester. In the mall building which houses the aquarium there is also an atrium with a mermaid fountain. map
The fountain has 6 mermaids around the edge of the fountain, with 6 dolphins in the center and 4 nudes on the second tier.
The center of the building was originally open to the sky, but was fitted with a glass roof in 2019, shielding the atrium (and the fountain and the rest of the building) from the Manchester weather.