Ekenäs slott in Linköping

You're standing at Ekenäs Castle, just outside Linköping in the Swedish province of Östergötland. Take a look at those tall white walls and that steep roof. Square towers with Baroque domes rise at the corners. The castle sits on a rocky outcrop, and there used to be a lake all around it, called Teden. That water made a handy natural defence. In the nineteenth century the lake was drained to gain farmland. It didn't quite work out: what they mostly got was marsh.