Doppelkirche Schwarzrheindorf (Church of Saint Mary and St. Clement in Schwarzrheindorf), Bonn

The Church of Saint Mary and Saint Clement is a remarkable Romanesque double church, built in 1151 as a private chapel for Arnold II of Wied and consecrated in the presence of King Conrad III. It later became a Benedictine nunnery under Arnold’s sister, Hadwig. The church's design consists of two stacked worship spaces: the lower church dedicated to Saint Clement and the upper to the Virgin Mary, complete with a dwarf gallery and a central tower-a central-plan layout inspired by the Palatine Chapel in Aachen.

A highlight for visitors is the well-preserved 12th-century fresco cycles in both upper and lower chapels. The undercroft showcases vivid biblical scenes from the Book of Ezekiel, uncovered beneath whitewash in 1863, while the upper chapel features a majestic Majestas Domini fresco with the church’s original patrons at Christ’s feet.

The church’s architectural elegance extends beyond decoration. The dwarf gallery, wrapped around the apse and transepts, offers an elevated walkway and visual rhythm punctuated by Romanesque capitals reminiscent of those in Maastricht-echoing Arnold II’s earlier building projects. The external stairway to the upper chapel once allowed noble or religious patrons to participate in services apart from lay worshippers below.