Here are a few photos of architectural details at the Château du Moulin, located near the town of Romorantin in the Loir-et-Cher (France). I was there again on July 2, 2016, after previous visits in 2000, 2003, and 2008.
The guide said this elaborate geometrical pattern in the brickwork seems to depict an African game called le jeu des crottes de chameau, played by children in the Sahara Desert. That would be "the camel dung game", for which the "board" is traced in the sand by the people who play it. Nobody knows why the pattern appears on a such an old wall in central France.
This is the coat of arms of the family of Philipped du Moulin, who had the château built in the last quarter of the 15th century. He wasn't really a nobleman, but he had saved the life of the French king during a battle in Italy. The king knighted or ennobled him on the spot and helped him build this château in the Sologne. Those are two lions carved into the stone.
Windows like these, above and below, are called fenêtres à meneaux, or mullioned windows, and are characteristic not of fortified medieval châteaux but of buildings designed to serve as comfortable residences.
Such windows show that the Château du Moulin is a transitional structure, built as the tumultuous Middle Ages and the 100 Years War waned and the more peaceful era called the Renaissance began in France, around the year 1500. The larger windows let a lot more daylight shine into the building, making it a more pleasant place to live.