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Beatenberg puts Lake Thun below you, with the Niederhorn offering a higher viewpoint when the lifts are running. A meal and a short prepared winter walk can be a full outing. Check the open route before choosing it; a summer walking line on a map does not tell you what is passable in snow.
The Niederhorn-to-Vorsass sledge run is a more active choice, with bends and steeper sections that need steering and braking. Hire and mountain tickets need checking separately. Night sessions have their own booking and seasonal dates. An open autumn cable car does not establish that any winter activity is operating.