Imagine you’re in a sauna, eyes closed and breathing in the hot steam. Feeling cleansed, relaxed and having achieved your zen, you get up and step out of the steam house into the middle of… Marden Henge? It sounds strange, but an amazing discovery in Wiltshire is throwing a whole new light on the way we think henges might have been used in Neolithic Britain.

Wiltshire is one of England’s most beautiful counties, and as recent research has shown, the land along the River Avon is absolutely packed full of Neolithic henge monuments, many of which date back well over 4,000 years. Although Stonehenge is the most famous, Marden Henge (less than 10 miles away) is just as rich in fascinating archaeology and is actually ten times bigger.

These henges, and the landscape they sit in, have been linked time and time again to ancient religions, rituals and ceremonies in Britain, and many experts have in fact theorised that they were also visited by Neolithic and Bronze Age people from all over Europe.

Just to add another element to the region’s long-debated mysteries, one hot summer’s day on an excavation at Marden Henge last year, archaeologists from the University of Reading found something unlike anything ever found at a henge before.

Right inside the circular enclosure, they found the outline of a building with a chalk floor, but soon, other features started showing up.

Just outside the walls, the archaeologists also found the remains of a huge, external fire, with charcoal, ash and fragments of burnt local, sarsen stone.

But as they carried on excavating, something even more intriguing emerged. Inside the walls, right in the middle of the building, they found an area of scorched earth – heated so much it had discoloured the white chalk to an orangey colour. Unlike the external fire, there was no charcoal. What then, was the source of the heat?

Jim Leary, the University of Reading’s fieldschool director who led the excavation, is proposing what initially sounds like quite a surprising theory.

“I think what’s happening is that people are heating up the stones on the external fire, and then carrying them into the building and placing them on the internal hearth.

And then they’re sitting on the ledge, pouring water on the stones to create steam and using the room as a sauna, or sweat lodge”, says Jim.

“That would explain the lack of charcoal inside the building. What’s more, the building is very well made, with a very substantial ledge perfect for sitting on, and the hearth really does dominate the whole space – there’s no room to do anything else apart from sitting around it. There’s no living space”.

This might be the first evidence of a sauna at a henge site in Britain, but it’s not a theory that’s come out of the blue. The ethnographic record is full of examples of people using steam to cleanse the body in ceremonies, and archaeologists have also found plenty of evidence that people were building and using saunas thousands of years ago around the UK, and even further afield.

In the far-flung Scottish island of Orkney, archaeologists found a Bronze Age sauna among 30 other buildings. Likewise, there are several sites along the Atlantic coast of Spain and Portugal, such as the Iron Age settlement of Citânia de Sanfins where saunas and steam rooms were being used – long before the Romans arrived – and which have also been linked to ancient religious practices.

“This is a landscape filled with temples and ceremonial monuments. It’s not hard not to imagine the act of sitting in a small, enclosed room full of hot, purifying steam being part of Neolithic people’s religious or ritual practices” says Jim.

The act of cleansing the body before, during or after important ceremonies is certainly something we would associate with modern spiritual beliefs, and given that similar ‘steam room’ structures have been found at different sites, from different time periods around Britain and into Europe, we’re left wondering just how far back does the practise of building and using steam rooms in Europe really go? And more importantly, what was their cultural significance?

We probably won’t ever be 100% sure what was going on at Marden Henge, but we sure would love to find out!

Luckily, we’ll be digging at Marden Henge in July 2016, to help Jim solve the mystery, and you can come and dig with us!

So, get your trowel (and your towel?!) ready! Who wouldn’t want to get into a sauna with a bunch of archaeologists after a hard day’s work? On second thoughts, maybe forget the towel after all…