The first "Neolithic" long barrow to be built in the UK for 5,000 years, is attracting interest from all over the world.
The burial chamber at All Cannings near Devizes in Wiltshire will contain niches housing urns of cremated ashes, and is set to be finished later this year.
Developer Tim Daw, who owns the farmland on which it is being built, said he was "absolutely thrilled" with its progress.
"It's turning out so much better than I could possibly imagine," he said.
"A lot of that is down to the stonemason, coming up with the idea of how to build it and insisting on doing it the proper way, using real traditional materials and methods. That's paying off in spades, with the quality of it and the feel of the place.
"For some of it, the stone has almost told us how to do it. At the entrance, when they fitted together it just felt right and it looks right."
Mr Daw said he had always had a passion for archaeology and the idea for it came out of a "classic pub conversation" - "Wouldn't it be nice to get buried in a long barrow?".
"Then I was walking round the farm one winter's morning and it was misty, very quiet and the sun was just rising, and I thought, 'I wouldn't mind spending eternity here'," he said.
"I thought, 'You could put a long barrow here with the winter sun coming in'. The idea all came together very quickly."
When the barrow is complete people will be able to pay to have ashes in urns stored within chambers inside the mound - some niches have already been sold - as an alternative to a crematorium.
"People have bought niches right from before we had even broken the ground," said Mr Daw.
"Someone from California has bought a niche, and she's very welcome.
"I'd love to have this as a meeting place, as so much of the Neolithic was about in Wiltshire, with people from all areas coming together."
Stonemason Geraint Davies described it as "not your usual job" and a "once in a lifetime opportunity".
"I saw an article about it in the The Times last year [when plans for it were submitted]," he said.
"It stated it was going to be in concrete, and we thought something like that needs to be in natural stone, so we approached Tim and he let us do it.
"I quite like archaeology. It's fascinating to go to Stonehenge and see how they managed to construct that."
"I'm trying to build it in a way [the Neolithic people] could have done it in their time."
Mr Davies, and his apprentice, are from Bedford and live in a caravan on site while work continues.
"We couldn't pass up on this. It's something special," he continued.
"It's strange really. We haven't built a long barrow for 5,000 years, but then about six weeks ago we had another enquiry for one.
"They want a burial chamber built in central London to hold some art.
"They're like London buses. You don't get one for 5,000 years and then all of a sudden two come at once."