Where it sits
Thun belongs to the Bern Region. The station and the lake piers sit in the same town. Bern is the capital upstream on the Aare. Niederhorn, Niesen, Stockhorn and St. Beatus Caves are other outings around the lake, not this city day and not a Jungfrau substitute.
What you’ll see
Thun Castle is the fortress with museum and history. The old town holds Obere Hauptgasse and its elevated pavements. Schadau Castle and park sit by the water.
Lake Thun boats include the paddle steamer Blümlisalp as a named ship. Cruise hours are not a fact here. There is no Aare swim on this page.
A simple day
Arrive at Thun station. Walk the old town to the castle, then Schadau if you stay by the water. A lake boat is the optional extra. Return to the station. For Jungfraujoch, start another day from Interlaken on the Jungfrau page. Bern is the capital as a city walk.