Meiringen air base, also known as the Unterbach military airfield, is a Swiss military airbase located near the hamlet of Unterbach and the town of Meiringen, in the canton of Bern. It is one of three main airbases of the Swiss Air Force. The airfield is situated in the steep-sided alpine valley of the Aar river, with its single runway parallel to the river. It is flanked to the north by the main road to Meiringen, the river, and the Brünig railway line.