Lake Hallwil is a lake in the Swiss Mittelland and, like Lake Baldeggersee a little further south, is located in the Seetal valley. Lake Hallwil is a popular destination for day trips. In particular, Hallwyl Castle and the Pfahlhaus buildings are well known attractions. In the villages along the lakeshore there are many restaurants and beaches. A walking path of 22 kilometres runs around the lake.