IT has long been considered a dreamy depiction of the shallows surrounding Venice.
Known as Festive Lagoon Scene, Venice, it was painted by JMW Turner, who was a frequent visitor to the city in the 19th century.
But now it has emerged that the city that inspired him was somewhat less romantic - and considerably closer to home.
Art experts have identified the location as Portsmouth, not Venice.
The painting is one of two Turners thought for decades to be views of lagoons around the Italian city known for its gondolas, but is actually depictions of the Hampshire city famed for its naval associations.
Officials at Tate Britain have uncovered the mistake while researching a new exhibition.
Ian Warrell, curator of the exhibition Turner And Venice, said the works, painted in the 1840s, were wrongly classified in the 1960s when they were shown at the Museum Of Modern Art in New York.
They became grouped with other seemingly Venetian works by Turner in 1966 and that interpretation has gone unchallenged
since. Mr Warrell said: 'Many of the details do not readily sustain the current connection. …