The Roman fort in Caernarfon dates to around 70AD, and was built to garrison up to 1,000 soldiers
A museum cataloguing centuries of Roman rule in Wales is facing permanent closure, says the trust which runs it.
The Segontium Roman Museum in Caernarfon, Gwynedd is on a site which experts call one of the best preserved Roman fortresses in the world.
But cash from a five-year funding deal is running out, and the trust says it may not be able to open in the spring.
The Welsh Assembly Government says it hopes a solution can be found to save the centre from closure.
Segontium Cyf, a trust made up of local people, took over the running of the centre from National Museum Wales in 2003.
Since then, the day-to-day running costs of the centre have been met through a funding deal set-up by the national museum.
However, the chairman of the Segontium trust, Rhys Prytherch, says that cash is now running out, and they face the very real prospect of closing the museum doors for good in just a few weeks.
"We were given money for a five-year period by the National Museum and it is that money now which is drying up," said Mr Prytherch.
"That is the reason that we have to close it. We can't now afford to pay the staff, or the heating or lighting bills."
It's very sad. It's part of the heritage of the area... I think people are proud of it
Rhys Prytherch, Segontium Cyf
The museum was opened in 1924 after the site was excavated by the one of Britain's most famous archaeologists, Sir Mortimer Wheeler.
Dating back to around 70 AD, the Segontium site was the largest Roman garrison in north Wales, capable of housing up to 1,000 soldiers, under the control of the Roman forces at Deva - now Chester.
On an elevated position overlooking the Menai Strait with views of Anglesey and approaches from the Irish Sea, the fort remained the administrative centre for the area for around 300 years.
The site itself is so large that the whole of nearby Caernarfon Castle could fit into the garrison twice.
According to Raimund Karl, professor of archaeology and heritage at Bangor University, the fort remained historically important for more than 1,000 years.
"It played an important role, particularly in the medieval period through its association with Macsen Wledig, or Magnus Maximus, one of the British Roman emperors, or one of the pretenders to the Roman emperorship," said Prof Karl.
"It's seen as one of his primary sites with which he was associated."
It opened in 1924 after excavation by archaeologist Sir Mortimer Wheeler
The link to the Roman leader was seized on by members of royal Welsh households, keen to claim they were direct descendants, and legitimate rulers in Wales.
The figure also features in the Welsh Mabinogion stories, retelling how Macsen Wledig had a dream about a beautiful woman, later to find her at Segontium.
Regardless of any truth in the folk tales, or whether the Roman leader ever set foot in Caernarfon, Prof Karl said it did not impact on the importance of the site.
"It's one of the best preserved Roman forts in Wales, if not the world," he said.
The museum is due to close for its annual winter shutdown at the end of November.
"Unless we can find another source of funding, it will remain closed," said Mr Prytherch.
"It's very sad. It's part of the heritage of the area. I think people are proud of it, they may not visit as often as they should, but I think they are proud of it."
The trust is already in discussions with the national museum over what may happen to the current exhibits it houses in Caernarfon, including coins, jewellery and pottery.
The Roman ruins, which are on land owned by the National Trust, will remain in the care of the assembly government's heritage arm, Cadw.
The assembly government added: "Despite best efforts, Cadw is disappointed to hear that Segontium is facing closure. We remain hopeful that a solution regarding the future of the centre can be worked out."
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