Benken has an area, , of . Of this area, 72.8% is used for agricultural purposes, while 12.6% is forested. Of the rest of the land, 9.1% is settled (buildings or roads) and the remainder (5.5%) is non-productive (rivers or lakes). The municipality is located in the See-Gaster
Wahlkreis (constituency) along the
Linth river. The
topography of the land has changed drastically in the past centuries. During the
Middle Ages the village was along the swampy, winding river. Following the Linth river control project in 1807-23 and the Melioration project of 1941–64, the village is now surrounded by rich farmland. It consists of the
linear village of Benken along the Linth and the
hamlets of Giessen, Sand, Rötli, Dorf, Räbli, Halden, Starrberg, Unterhalden, Schmittenäcker, Schmitten as well as scattered farmhouses in the valley and on the Büchel hill. ==Coat of arms==