Chapelle St-Louis-de-la-Salpêtrière

This austerely beautiful chapel, designed by Libéral Bruand and completed in 1677, features an octagonal dome in the centre and eight naves in which the sick were separated from the insane, the destitute from the debauched.

Around the chapel sprawls the vast Hôpital de la Pitié-Salpêtrière, founded on the site of a gunpowder factory (hence the name, derived from saltpetre) by Louis XIV to house rounded-up vagrant women. It became a centre for research into insanity in the 1790s, when renowned doctor Philippe Pinel began to treat some of the inmates as sick rather than criminal; Charcot later pioneered neuropsychology here, famously receiving a visit from Freud.

Salpêtrière is today one of the city's main teaching hospitals, but the chapel is also used for contemporary art installations, notably during the Festival d'Automne, when its striking architecture provides a backdrop for artists such as Bill Viola, Anish Kapoor and Nan Goldin.