Châtonnay is a farming village in the Bas-Dauphiné, on the gently rolling ground between Bourgoin-Jallieu and the Bièvre plain. Its surroundings are typical of this part of Isère: a mix of maize and wheat fields, pastures, hedges and small woods, with stone farmhouses and church towers on the low ridges.
About twenty-five kilometres to the east lies the Lac de Paladru, a lovely glacial lake surrounded by hills. Its waters have preserved the remains of lake villages from the Neolithic and from around the year 1000, when a community of farmer-knights lived on the shores. The archaeological finds are displayed in a museum at Charavines, and the lake is popular for swimming and boating in summer.
As a start and fuel stop, Châtonnay is close to the A43 and to Bourgoin-Jallieu, where there are plenty of services. The village itself has limited facilities, so it is wise to fill up in Bourgoin or La Côte-Saint-André before setting off into the hills. From here, the roads east towards the Chartreuse are excellent, climbing gradually through the hills before the dramatic limestone cliffs of the massif come into view.
The local roads are winding and pleasant, with short climbs, blind bends and good views. Surfaces are generally good, and traffic is light. Watch for farm vehicles and gravel at field entrances. In early morning, mist often lies in the hollows, and the light over the hills is beautiful.