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Bern is a good day to leave the mountain checklist at home. Walk from the station into the old town, follow the arcades, and let the fountains and side streets interrupt you. The river views are worth stepping out from under the covered walkways, even on a day chosen for uncertain weather.
The Parliament Building makes a worthwhile stop from outside. Going inside is a separate plan: check the official tour calendar, available language, reservation process and identification requirements. Do not build the day around a walk-in tour. Leave space for a café and an unhurried walk back.