In a remote forest clearing in Burgundy, France, a 13th-century castle is slowly being constructed using only the tools, techniques, and materials that would have been available to the builders of the day. It’s archaeology in reverse.

The Guédelon project was started in 1997 at this location, which was chosen because it was near an abandoned stone quarry, a pond for water, and in a forest that could provide wood. The whole exercise is an experimental archaeology endeavor that seeks to discover what it would have been like to create a castle centuries ago, not by making guesses from artifacts from the past, but by experiencing it in real time. Knotted rope is used to make measurements, stone is imperfectly cut to denote the station of the castle’s owner, and rock is chiseled by hand.

There is even a period accurate back story attached to the project that informs the design and construction. According to the story, the castle (actually a chateau, although to modern eyes it could certainly be described as a castle) is being built by Guilbert Courtenay, aka Guilbert de Guédelon, a low level noble who is constructing the new home in order to advertise his wealth and station. The elaborate back story, which was specifically started in a fictional 1229, helps the creators speculate as to exactly what type of amenities the space might have.

The project is ongoing, and is expected to be completed in 2020. It can be visited, and is, by around 300,000 people a year. Not only are many of the members of the project in period dress, but there is also a medieval restaurant to eat at. It may seem a bit kitschy on the surface, but their methods are pretty hardcore.