Chateau de Guedelon is a real 13th century castle, or at least, it will be when they finish building it:
The Chateau de Guedelon was started in 1998, after local landowner Michel Guyot wondered whether it would be possible to build a castle from scratch, using only contemporary tools and materials.
Today, the walls are rising gradually from the red Burgundy clay. The great hall is almost finished, with only part of the roof remaining, while the main tower edges past the 15m (50ft) mark.
Builders use sandstone quarried from the very ground from which the castle is emerging.
[. . .]
The Guedelon site was chosen because it contained all the necessary materials: plentiful oak from the forests, as well as clay and water. Stone from the quarry had actually been used in the building of real-life medieval chateaux.
