Orebro - Castle in the River. Stolid Fortress.

Orebro, in the south-central part of Sweden, on the Svarta River, placed its castle wisely:  where future tourists would love it on its own island.  The town was a commercial and political center, coming to prominence in the 14th Century.  Later remodelings and renovations of its castle buttressed its function from defense, to commercial display of power, with windows for looking out; no arrow slots.  The crenellated roofline embellishes one end.  The bulbous towers are echoed in other structures nationally, from monasteries, see http://www.satie-archives.com/web/arkitekt.html
and other castles.  Very stolid. Solid. Heavy. Protectionist, not imaginative, is that so?  This is a land with few natural defenses, such as mountains, and coastal areas are flat, and inlands have lovely lakes and farmland, so this architecture makes sense:  once invaders landed, the Swedes fared best with musclebound fortresses.

Orebro, Sweden, castle on island

The town is known for Engelbrekt Engelbrektsson, hero in a rebellion against Denmark, 1390's-1434 or so; and Church Reformers Olaus and Laurentius Petri.  No connection to the petri dish?  Denmark, Sweden and Norway had been united under King Erik of Pomerania (Germany).