A garden step from a home in Devon has sold for more than £550,000 at auction.
The carved granite step is believed to be a very rare Sri Lankan Sandakada Pahana - or moonstone - similar to those found in temples dating from the Anuradhapura period (c400BC-1000AD).
In January, Bonhams estimated the temple stone at between £20,000 and £30,000, but it made £553,250.
Previous owners, Mike and Bronwyn Hickmott, said they were "overwhelmed".
'No track record'
Bonhams said because the stone was so rare, it had been difficult to estimate how much it would sell for.
"There are only seven of them in the world, so there's no track record," a spokesman told BBC News.
"We estimated between £20,000 and £30,000, but there's been so much interest in it from around the world, we weren't totally surprised at what it eventually went for."
Mrs Hickmott was four years old when the artefact was found in the garden of a house bought by her parents in Sussex from a tea planter who had lived in Sri Lanka.
When she and her husband decided to move to a smaller home last year, they asked Bonhams to look at the 8ft x 4ft (2.4m x 1.2m) stone on their garden path.
"I'd never seen anything like it," Sam Tuke of Bonhams in Exeter said.
"The quality and depth of the carving was quite extraordinary - and I thought 'I need to find out what it is'."
After researching as much as he could, Mr Tuke passed the information to Alice Bailey, the head of Bonhams' Indian and Islamic Art.
The stone, which has lions, horses, elephants, birds and Brahim cows carved on it, went under the hammer at Bonhams' Islamic and Indian sale in London on Tuesday.
After the sale the Hickmotts said: "We are overwhelmed with the price achieved. It goes beyond all our expectations."
"We had been turned away by other international auction houses as well as television antiques shows.
"Everyone pooh-poohed our belief that the stone was special... it was only Sam's determination to research the stone that has led to this happy result."
Bonhams said it was unable to disclose who the new owner of the artefact was.