Princess Mathilde, niece of Napoleon, held one of the most brilliant salons of nineteenth-century France at her château in Saint-Gratien. Flaubert, the Goncourt brothers, Sainte-Beuve, Maupassant and many other writers and artists gathered there in the summers, and the conversation, it was said, was the best in France. The château still stands, though not open to the public, on the edge of the lake of Enghien.
Saint-Gratien shares that lake with its neighbour, and it is a quiet, residential town of villas, gardens and tree-lined streets. Marshal Catinat, one of Louis XIV's best generals, retired here and died in 1712, and his name is still on streets and a school.
It is a curious end to a weekend in the Morvan. Two days ago you were on empty granite roads among beech forest and lakes where nobody spoke above a murmur; now you are threading through the northern suburbs of Paris, counting traffic lights. The last stretch is slow, stop-start and full of buses, and a little patience goes further than a lot of throttle.
The reward is the lake. From the Saint-Gratien shore you look across the water to the white casino and the old spa buildings of Enghien, and in the evening, with rowing boats tied up and ducks arguing in the reeds, it has a gentle, provincial air that seems to belong to Mathilde's century rather than ours.
Practicalities are easy. The town has fuel and shops on its main roads, and the cafés of Enghien are a five-minute walk round the shore. Leave the bike, walk a loop of the lake, and let the Morvan settle into memory.