Visitors to a South Shields seafront park could find themselves with the blues over its odd-looking lake.
People have been left rubbing their eyes after the water in South Marine Park was turned a stunning green-blue colour in recent weeks.
South Tyneside Council has said the move has been made to make it look better – as well as killing off any algae growing in the water as the weather gets warmer.
The boating lake is home to a large number of swans, ducks and geese, and the authority has said the colouring will not cause the wildlife in the water any problems.
A council spokeswoman said: “The lake is a key feature of South Marine Park and it is important that we keep it looking its best.
“We regularly use a non-toxic pond dye in the water.
The pond dyes are safe to use and not harmful to local wildlife.South Tyneside Council
“This not only gives the lake a blue colour, but helps to keep unsightly algae and aquatic weeds at bay, by filtering out sunlight and disrupting the growth process.
“The pond dyes are safe to use and not harmful to local wildlife.”
The park was created more than 100 years ago and was designed by Matthew Hall, the borough’s surveyor and engineer, while gardener John Peebles began work in 1886 and to create the park using old waste spoil tips.
Its construction cost £20,000 and it was opened in June 1890 by Sir John Mowbrary, a former MP for Durham and ecclesiastical commissioner.
The park is registered under the Historic Buildings and Ancient Monuments Act and within the Register of Historic Parks and Gardens by English Heritage for its special historic interest.
It makes up a chain of the three seaside parks, neighboured by North Marine Park and Bents Park.
The Friends of North and South Marine Parks volunteer and organise a host of events including litter picks, walks and music sessions.
More about their work can be found via http://parkfriends.org.uk/.