Pfäffikersee (or Lake Pfäffikon) is a lake in the canton of Zürich, Switzerland, near the town of Pfäffikon. It is 2.5 km long and 1.3 km wide at the middle. The lake was created in the last ice age when a moraine blocked off the ability for the lake to empty north towards Winterthur. There is also a hiking trail around the lake that people often bike and walk on, and the area is considered protected lands, among them the Robenhauser Ried. In Roman era, along Pfäffikersee there was a Roman road from the vicus Centum Prata (Kempraten) on Obersee–Lake Zürich via Vitudurum (Oberwinterthur) to Tasgetium (Eschenz) to the Rhine.