Rapperswil's Old Town is dominated by the sturdy turrets of its much-photographed 13th-century castle. Climb up to its terrace for views over a jigsaw of gables and the lake. On a cloudless day it's possible to make out the outline of the Glarus Alps.The castle now harbours the Polenmuseum. Wander the lovely castle grounds and you might well come eye to eye with fallow deer.