Mists in the Brenne

They say there are over 1000 lakes like this in the Brenne in central France, mainly man-made.  When you say something is man-made, you tend to think it's recent, but the earliest of these were created in the 11th and 12th centuries, to make the marshy land more usable, and to provide sources of water during drier times.  Later, in the 13th and 14th centuries, fish farming started, another term normally thought to be modern.  These fish, carp, were raised to provide food during the 140 or so days of fasting demanded by the church and fulfilled both religious and economic needs.

Nowadays the Brenne is a regional natural park, a nature reserve, and an important stopping off point for migratory birds.