In the former fort "Aue" at the eastern exit of the city Haslach stands since the first half of the 17th century a chapel. Originally it was called "Aue-Kapelle". Named after the neighboring mill, it has been called the "Mill Chapel" for a long time.
The chapel was built in 1622 and goes back to the initiative of the Haslacher senior official Simon Finkh (1580 - 1648). At first she was very small and modest at the beginning of the Thirty Years' War, but in 1652 she got an extension. The occasion was the vow of the wife Margaretha Dorothea Finkh, b. Gebele (1600 - 1663) and her brother, the landowner Jakob Gebele (1601-1675) at the outbreak of the plague in 1635. However, this could only be redeemed years after the Great War.
Due to troubled times, the chapel was consecrated in 1661 by Auxiliary Bishop Gabriel Haug from Strasbourg. She received the title of the "Immaculate Conception of Mary" (8 December) at the time of the consecration and, as a further patronage, Saint John Nepomuk. The front of the chapel adorns a picture of the well-known bridge saint, built in 1729 by Pope Benedict XIII. was pronounced holy. Another depiction is inside the chapel together with that of St. To admire Franz Xaver. The latter is mentioned in the 17th century as the patron of a men's brotherhood, which bore his name. According to the records of the agenda (workbook) of the Haslacher monastery from 1753, the Capuchins looked after the mill chapel. Twice a week they celebrated Holy Mass there. The Franz Xaverius Brotherhood led by them held their prayers and meetings there.
According to a visitation report about the parishes of the chapter of the Land of Lahr from the year 1666, the Mill Chapel had three altars. After repair work in the 19th century unfortunately only the high altar was left. Because of the ever-increasing road traffic, the Mill Chapel was canceled in 1974. Fifteen years later, it was able to be rebuilt in almost the same size as before.
In the tradition of the Haslacher population, the mill chapel plays an important role in the feast of St Peter's celebration (22 February), the traditional stork day. Here after the prayer of the "angel of the Lord" begins the procession of the children.