The impressive building of the Mannenberger Mühle used to stand on the meadow between Kempt and the edge of the forest. Of all the mills in the Illnau community, the Mannenberger mill had the best energy ratios because it used both the water from the Kempt and the Grendelbach. It is mentioned for the first time in the documents in 1482, when the knight Konrad Schwend sold the Würgeln and Mannenberg mills to his fief miller Konrad Himmel as inheritance. Towards the end of the 16th century, representatives of the old Tagelswang family of Wegmann married at the two mills. This family soon belonged to the most influential families in the Illnau community. In 1675, Jakob Wegmann had the Mannenberg mill rebuilt in a splendid half-timbered style by Zimmermann Urlich Bruzer. As one of the first and most beautiful half-timbered buildings in the region, it was an excellent testimony to rural architecture. In 1854 the Wegmann family sold the entire property of the Swiss Nordostbahn company. the railway embankment built in 1855 cut off the water supply to the Mannenberger Mühle and resulted in the cessation of centuries-old operations. The historic building was demolished in 1871. Apart from the sandstone cave, which the mill family had used as a natural cellar, nothing today reminds of the proud past of the Mannenberger mill.