The painting is on display in London until 4 December
A rare Turner masterpiece, expected to fetch up to $16m (£10.6m), has gone on display in London.
The Temple of Jupiter Panellenius, one of the most important Turner oil paintings remaining in private hands, will be auctioned in January.
It is touring Paris, London and Los Angeles before being sold at Sotheby's in New York.
It depicts an ancient Greek scene of figures dancing a national dance with a temple in the background.
It has been in the private collection of prominent fine art dealer Richard L Feigen for more than 25 years.
Emmeline Hallmark, head of British paintings at Sotheby's, said: "What makes this picture so valuable is the rarity factor, and the fact it's a masterpiece.
"There are less than 20 Turner oil paintings left in private hands.
"Turner painted it at the height of his career, when he was at his most famous. It was painted to hang in the summer exhibition at the Royal Academy in 1816 when he knew everyone would come to see what Turner had come up with next.
"He purposefully painted it to be one of his most famous and rare works.
"It was painted the same year that the Elgin Marbles were in London and debate surrounded whether they would remain here.
"At the same time Greece was occupied by the Turks, so this nostalgic painting shows the Greeks at a time when they were free and liberal."
A number of high-profile paintings have failed to reach their estimate at auction recently, but Sotheby's is confident the state of the economy will not impact on the Turner sale.
"What we've seen is, despite the current economic climate, trophy pictures will sell whatever," Ms Hallmark said.
"These are singular chances that are so rare that people will find the means to buy them no matter what."
The Temple of Jupiter Panellenius will be on display at Sotheby's, London, until 4 December.