CHAMPS ELYSEES AND INVALIDES.: Much of the huge classical building is now occupied by the Musée de l'Armée, a stagerring display of arms, armour and other war paraphernalia from prehitoric times to the two World Wars. The Musée des Plans Reliefs consists of fascinating scale-models of French fortified towns. Also on the site are Eglise Saint Louis soldiers'chapel, and the Eglise du Dôme, a hoghly decorated example of Louis XIV Baroque architecture, with a huge, gilded cupola visible from miles. Inside in colourful splendours is the porphyry sarcophagus of Napoléon.