The wall would be parallel to the rue Etienne Marcel. N° 20 Robert d'Artois had the Hotel d'Artois built in 1270, then outside Paris, but against the wall. When he died the hotel was tansferred to the family of the Ducs de Bourgogne, where they lived. The next owners were Philippe le Hardi (1342-1404) then Jean Sans Peur (1371-1419) who lived there from 1404.

In 1408 he had a tower built in the center of the hotel. He wanted to have a bedroom well protected and not eaisly accessible for he was afraid of being assassinated . In fact, in 1407 ha had the Duke Louis d'Orleans assassinated (king Chalres VI's brother), He feared a revenge.

This rectangular tower is the only specimen of military architecture dating from the Middle Ages left in Paris. It is 23 meters high from the ground, 10 meters wide and 4,5 meters deep.

Visiting hours : Wednesday, Saturday and Sunday during school time and every day, except Monday during holliday season (Paris school holidays) Visiting time : 1.30pm-6pm