Les Invalides was originally just what it sounds like – a hospital with nursing care for wounded war vets. It is now home to the Musée de L'Armée, with over half a million items on display; the star of the show, however, is the Tombeau de Napoléon - Napoléon's Tomb. It's located in St Jérôme's Chapel at Les Invalides, although to many it seems like a cathedral with its open space, gilded details and gleaming marble at every turn.
Interestingly, this is not the original resting place of Emporer Napoléon; he died in 1821 while in exile on the island of St Helena, and was buried in an anonymous tomb. It was not until 1840 that his remains were brought back to France, complete with a funeral procession down the Champs-Élysées before being interred at Les Invalides.
Les Invalides is located at 129 rue de Grenelle in the seventh arrondissement, and is reachable by the M8 (Saint François-Xavier) or the M13 (Invalides).