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Spiez has two centres to think about: the railway station above town and the bay below. Walk down towards the castle, harbour and water, then leave time to sit or follow the shore towards Faulensee. The return to the station is uphill; with luggage or tired legs, check the local bus.
For a stay, choose the address around your everyday journeys. A place beside the water and one near the station offer different conveniences. Trains connect towards Thun, Interlaken and the Kandertal, but reaching a Jungfrau-region village still means an onward journey through Interlaken.