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When comparing the apartments here with Airbnb, begin with the actual home and address. These stays are around Lake Thun, outside central Interlaken and the mountain villages. Choose this lake because you want time here too. If every morning starts in the same mountain village, sleeping there may suit you better.
Compare the same dates, guest count and apartment, then read the full price, cancellation terms and arrival details on each booking page. Direct booking is not automatically cheaper or more flexible. Look at the sleeping arrangement, stairs, kitchen and walk from the stop. The guide to choosing a base helps with the location decision.