Lagny-sur-Marne sits on the river Marne about thirty kilometres east of Paris, a busy town with an old centre, a riverside quay and a large, unfinished Gothic church, Notre-Dame-des-Ardents, all that was completed of an ambitious abbey church begun in the thirteenth century. The town was an important market in the Middle Ages, part of the network of Champagne fairs, and Joan of Arc fought near here in 1430, shortly before her capture at Compiègne.
Today, Lagny is part of the Marne-la-Vallée area, and Disneyland Paris lies just to the south. The Marne itself is a lovely river, with wooded banks, islands and locks, and the riverside paths are popular with walkers and cyclists. The towns along the river have a gentle, old-fashioned charm.
As a start and fuel stop, Lagny is convenient. There are service stations and supermarkets nearby, and the A4 motorway provides quick access to Paris and the east. The roads north towards the Multien and the forests of Chantilly and Ermenonville are pleasant, with gentle curves through farmland and woods.
Traffic can be heavy around Lagny and Marne-la-Vallée, especially at commuting times and on weekends near Disneyland. Once you are out in the countryside, the roads become quieter. Surfaces are generally good. The Marne valley upstream, towards Meaux and Château-Thierry, offers a scenic route through vineyards and villages.