Hôpital Hôtel-Dieu AP-HP
L’Hôtel-Dieu de Paris est le plus ancien hôpital de la capitale.
This is an very old hospital and you can freely enter inside just to visit the inner court which is amazing and play piano if you like.
The Hotel Dieu is the oldest hospital in Paris. The building is magnificient. Every one goes to Notre Dame, but few people take time to go see the gardens of the Hotel Dieu, but it's really worth it !