Popperöder Brunnenhaus, Water well building in Mühlhausen, Germany

The Popperöder Brunnenhaus is a massive stone building with a timber-framed upper storey, built in 1614 by master builder Hans Rinke and carpenter Matthes Lauberbach. Its ground floor opens in three round arches toward the spring, and a porch with two Tuscan columns faces the circular travertine spring basin. The slate roof carries five small ornamental turrets, and the timber frame is decorated with curved St Andrew's crosses.

The spring emerged in 1199 following an earthquake that created a natural sinkhole, and the well house itself was built in 1614 under Mayor Gregor Fleischhauer. The building was developed to make the already valued water source accessible and usable for the town.

The name Popperöder comes from the abandoned village of Poppenrode, deserted since 1552. Every year since 1605 a Brunnenfest is held at the start of summer, organised in turn by Mühlhausen primary schools: a colourful procession walks from the school to the well house, where traditional Brunnenfest dances are performed and the spring is decorated with bouquets weighted with stones and lowered into the shaft. Visitors also throw coins into the well to make wishes; many aluminium coins from the DDR era remain in the sediment.

The well house stands about four kilometres west of Mühlhausen's centre, near the Schwanenteich recreation area, at the site of the deserted village of Popperode. The spring lies at 227.6 m above sea level. The exhibition inside is open only during wedding ceremonies and on the day of the Brunnenfest, so the exterior and the spring enclosure are what most visitors see.

The spring's basin is 3.8 m deep and holds a permanent stand of common mare's-tail (Hippuris vulgaris), a plant rare and endangered in Thuringia. Coins thrown as wishes still collect in the sediment despite yearly suction cleaning, many of them aluminium pieces from the GDR era.