Oberägeri, until 1798 simply known as Ägeri, is a municipality in the canton of Zug in Switzerland. Oberägeri first appears in historical doc…Oberägeri, until 1798 simply known as Ägeri, is a municipality in the canton of Zug in Switzerland. Oberägeri first appears in historical documents in 1150 as Agregia. In 1538 it was mentioned as Ober Egere.