1. Moon mechanism and exterior
The cathedral is preserved in its original 18th-century form. The silhouette of the church in one of the corners of the Union Square attracts you from a distance and urges you to get closer. The dominant architectural style is late Baroque with Byzantine elements.
The mechanism that moves the moon is unique in Europe. The half-golden, half-black moon is driven by a mechanism designed and built by Georg Rueppe in 1793, which indicates the phases of the moon. It is located in the cathedral tower.







