The vineyards between Spiezberg and the castle are part of the town's identity. They are small by European wine-region standards, but the setting above Lake Thun gives them a drama that larger vineyards often lack.
Follow the paths above the bay for views over the castle, harbour, and Niesen. If you can taste local wine while you are here, do; Swiss wine rarely travels far, and Spiez is a good reminder that the country drinks much of its own production.