These 11 – including one further on the nearby Greifensee and Robenhausen on Pfäffikersee lakeshore – prehistoric pile-dwelling (or stilt house) settlements were built from around 5000 BC to 500 BC and are concentrated within an area of about 40 sqkm , on Lake Zurich respectively Obersee lakeshore in the cantons of Schwyz, St. Gallen and Zürich.