This grandiose complex houses a military museum, church, tomb, hospital, and military ministries, among other things. Commissioned by Louis XIV, who was determined to create a home for soldiers wounded in the line of duty, it was built on what was then the outskirts of the city. The first war veterans arrived in 1674—between 4,000 and 5,000 soldiers would eventually move in, creating a mini-city with its own governor. An on-site hospital was constructed for the severely wounded, which is still in service today.

As you cross the main gate, you’ll find yourself in a huge courtyard, the cour d’honneur, once the site of military parades. The surrounding buildings house military administration offices and the recently renovated Musée de l’Armée, one of the world’s largest military museums, with a vast collection of objects testifying to man’s capacity for self-destruction. The most impressive section is Arms and Armor, a panoply of 13th- to 17th-century weaponry. Viking swords, Burgundian battle axes, 14th-century blunderbusses, Balkan khandjars, Browning machine guns, engraved Renaissance serpentines, musketoons, grenadiers—if it can kill, it’s enshrined here. There is also a huge wing covering the exploits of everyone from Louis XIV to Napoléon III, another on the two World Wars, and a shrine to Charles de Gaulle. Also onsite is the Musée des Plans et Reliefs, a somewhat dusty collection of scale models of fortresses and battlefields.

The Eglise du Dôme is split in two, the front half being the light-filled “Soldier’s Church,” decorated with magnificent chandeliers and a collection of flags of defeated enemies. On the other side of the glass partition the Tomb of Napoléon lies under one of the most splendid domes in France. Designed by Hardouin-Mansart, it took over 2 decades to build. The interior soars 107m (351 ft.) up to a skylight, which illuminates a brilliantly colored cupola. Ethereal light filters down to an opening where you can look down on the huge porphyry sarcophagus, which holds the emperor’s remains, encased in five successive coffins (one tin, one mahogany, two lead, and one ebony). Surrounding the sarcophagus are the tombs of two of Napoléon’s brothers, his son, and several French military heroes. Don’t blame the over-the-top setting on Napoléon; the decision to transfer his remains to Paris was made in 1840, almost 20 years after his death. Tens of thousands crowded the streets to pay their respects as the coffin was carried under the Arc de Triomphe and down the Champs-Elysées to Les Invalides, where it waited another 20 years until the tomb was finished.