Nesslau-Krummenau had an area, as of 2006[ [update]], of . Of this area, 53.8% is used for agricultural purposes, while 36.5% is forested. Of the rest of the land, 3.2% is settled (buildings or roads) and the remainder (6.6%) is non-productive (rivers or lakes). The former municipality was located on both sides of the Thur river between the Speer and Stockberg and from the Silberplatten in the Säntis range over the Schwägalp Pass to Mistelegg. After the merger in 2005 it was, in terms of land area, the third largest municipality in the canton. It consists of the villages of Nesslau, Krummenau, Neu St. Johann, Dorf and Ennetbühl as well as the hamlets of Lutenwil, Krümmenschwil, Büel, Schneit, Laad, Schlatt (until the merger an exclave of Nesslau in Krummenau), Aemelsberg and Beiereggbis.