Fougères

The town is on the hill, the castle is in the valley – designed to block the valley, of course. The castle in medieval times was actually bigger than the town, and in time of troubles the whole population would move into the castle, which has wells, a stream, two water-mills and everything else needed for a long siege. It's a frontier town, in Brittany and on the borders of Normandy and Mayenne, and the meeting-place of eight main roads, and thus of immense strategic importance in its time, which explains the largest castle in Europe.