Plön has a castle on a hill, and the hill is what makes the town. The big, white, many-windowed building stands on a rise between two lakes, and from its terrace the view runs over the water, the islands and the wooded shore. The castle was built in the seventeenth century as a residence for the dukes of Holstein-Plön, and later served as a Prussian military school, where sons of the Kaiser were among the pupils, and then as a boarding school. It is not open in all parts, but the grounds and the terrace give a fine look at the lake.
The lake balcony is one of those places where the whole region becomes legible. You can see the way the glacier shaped the land: the long troughs of water, the rounded hills, the islands that are hills drowned to the neck. A small island called the Prinzeninsel lies in the lake, once the retreat of princes and now a quiet park with a bathing place. The town has a public beach on the lake, and swimming there is pleasant in summer, with the water clean and mild. A lifeguard is on duty in the high season, and the shallow, sandy entry is good for children.
Getting up to the castle is a short but pleasing climb on a cobbled road that is steep for a few hundred metres. Take it slowly, since the cobbles are uneven, and park at the foot if there is no space at the top. The road around the lake from there is among the best in Schleswig-Holstein, a smooth, curving ribbon with views of water between the trees, and it rewards a slow, unhurried pace. Evenings in summer are the best, when the lake takes on the colours of the sky.
Plön itself has about thirteen thousand people, with fuel stations at the edge of town, supermarkets and many cafés. A drink at a terrace on the lakefront is a fine way to end the afternoon. Be aware that the wind can pick up quickly on the open water, and sudden showers are common, so keep a jacket nearby. If you have time, take one of the little passenger boats that cross the lake, since from the water you can see the castle's full outline above the trees.