Located on the bank of the River Seine, the Hôtel de Sens, along with the Hôtel de Cluny, is the last vestige of medieval architecture in Paris (1475). The hotel was built for the Archbishop of Sens, a character who overshadowed even the Archbishop of Paris. It currently houses the Forney art library, thus conferring an altogether literary sheen on what is otherwise a military work of architecture. A cannon ball remains lodged in the walls near to the left turret as a sober reminder of the riots of 1830.*
* On a lighter note, the insatiable Queen Margot saw her young lover's throat slit by a jealous suitor in front of its beautiful Gothic gate. A wonderful, magical image I'm sure will come back to you this and every Valentine's Day.