Deep in the forests of northern Burgundy, history is in the making. Stonemasons hew at rough chunks of sandstone with tools produced from scratch in the forge by leather-aproned blacksmiths. The stone is transported by horse and cart to be raised to walls by workers in smocks marching in a wooden treadwheel operating pulleys capable of raising a tonne in eight minutes.

In the nearby wood, artisans have constructed a medieval flour mill based on a recent archaeological find. To their delight – and no little surprise – it works. Mobile phones, however, do not. And there are few concessions to those other perceived scourges of modern life: health and safety.

Outside the forest clearing it is 2014. Inside, it is 1245 and the fictional Guilbert Courtenay, aka Guilbert de Guédelon, is anxious to take possession of his new home: a modest chateau befitting his social station as a lowly aristocrat and knight who has fallen into royal favour.

Guédelon is a unique historical and archaeological project to build a chateau from scratch using medieval materials and techniques. Instead of digging down to solve the mysteries of history, workers at Guédelon are building up.

Such is the magic of travelling back eight centuries that 300,000 visitors flock to Guédelon every year and hundreds volunteer to join the workforce.

When the Guédelon project began 16 years ago, it was deemed essential to place the mini castle and its owner at a specific period of history. The year chosen was 1229, when Louis IX, later Saint Louis, was king of France, but at 15 he was deemed too young to rule.

As the story goes, his mother, Blanche of Castile, who holds the reins of power is informed of Courtenay's distinguished fighting for the royal army against rebellious barons and awards him a "licence" to build a modest castle.

Everything about Guédelon will reflect Courtenay's modest standing, which means he can afford to build a small chateau, but cannot afford a moat or architectural refinements.

A man at work at Guédelon Castle. Hundreds of people have volunteered to work on the project.

On the medieval building site, the present tense refers to the middle ages. The hundred years war (1337-1453) is still a century off, but an Englishwoman, Sarah Preston, originally from Bath, finds herself showing visitors around.

"Every element has to be referenced back to the 13th century. We ask ourselves, Guilbert de Guédelon is a low-ranking nobleman with limited resources so what are his options? Will he be able to afford a drawbridge that will take 57 felled trees and 66 iron nails? No," Preston says.

"This chateau is Guilbert sending a message to the medieval world about his power and wealth. There is no prison, for example, because a lord of his rank doesn't have the right to keep prisoners.

"At one point we realised the stonemasons were cutting the stones for the towers too perfectly, which just wouldn't h ave been appropriate. It would have suggested he had a lot of money and therefore a small army in the chateau, which wasn't the case."

Like all Guédelon workers, Preston has her "corde à treize noeuds", a rope with 13 equidistant knots used for measuring, marking circles and other geometric figures.

Much of the work is by trial and error. The right-hand section of chateau roof tiles is blacker than the rest due to the first few batches being left in the oven too long.

For the permanent workers, the volunteers and those who visit, often year after year to see how work is progressing, the project inspires passion.

"We are constructing in order to comprehend. From the first stone to the last tile of Guédelon we want to learn and understand," says Maryline Martin, the project's director general.

"When we started we thought about what a 13th-century chateau in this part of the world would look like, what the actual builders would be like, how they would work, with what materials. Our approach was scientific.

"We have succeeded on every level: human, scientific, archaeological, tourism. It's an adventure with a capital A."

Two years ago, French archaeologists found the remains of a flour mill, believed to date from the 13th century, in the neighbouring mountainous Jura region of eastern France. Working with Guédelon they attempted to rebuild it, to see if it would work.

"This was an exceptional experience. There were pieces that were a total mystery: we just couldn't work out what they were or where they went, but we approached things intellectually and we worked with the scientists.

A worker at the construction site of the Guédelon Castle. Photograph: Jeff Pachoud/AFP/Getty Images

"We even went to countries including Romania to see how their mills work, to see if that helped. Today, we have succeeded in building a working mill," Martin adds.

She rejects the idea that Guédelon is a bit Disney.

"It's very French that when something works we say it is because it's populist and not serious, that it is just a theme park. We refute this idea: the site is a medieval construction site. We use horses, stone, wood, water and if it rains we advise people to come in rubber boots because its medieval and not all nice and paved."

"We started with a history committee that was independent of us and approved the plan. It's experimental archaeology and it gives a better understanding and education that explains the heritage of the 13th century to the public. It's helping us decode the 13th century.

"Guédelon is built on the strength of its team of workers. The atmosphere, harmony and team spirit are extraordinary. We have people come and work with us who normally spend their days stuck to mobile phones and computers and want to experience something completely different – not just manual, but working as a team.

About 300,000 visitors flock to Guédelon every year. Photograph: Philippe Desmazes/AFP/Getty Images

Martin adds: "We are not just living the medieval life, it's a serious archaeological project. By decoding the 13th century we are helping people understand it."

What was going on at the time?



It is 1245 in Guédelon, in Burgundy in central France. King Louis IX is on the throne in France and King Henry III in England. Louis is married to Margaret of Provence and Henry to her sister Eleanor. The women are helping to mend relations between the two countries, riven by war since 1180 and not helped by Henry's disastrous invasion of France in 1230. In 1259 the two monarchs will sign the treaty of Paris intended to end the territorial conflict between the two countries. It will not prevent the hundred years war kicking off in 1337.

The rebuilding of what is now Westminster Abbey is being started on royal orders and the Seventh Crusade (1258 to 1254), to be led by Louis to avenge the fall of Jerusalem to the Khwarezmian Persian Sunni Muslim dynasty the previous year, has been proclaimed. It will lead to Louis's defeat, capture and ransom by the Egyptian army.

• This article was amended on 28 August 2014 because an earlier version referred to King Henry III "in the UK". This has been corrected to say in England.