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Spiez spreads up the hillside from its bay. The castle and vineyards give the waterfront its shape; higher up, the town centres on the railway station. Down at the harbour, a lakeside lunch can easily turn into an afternoon watching the boats.
The shore path towards Faulensee is the obvious place to stretch your legs. For a shorter wander, stay around the castle and bay. The climb back to the station is quite a different walk from the flat waterfront, so the local bus is handy on the way up.