Speyer Cathedral
(Imperial Cathedral Basilica of the Assumption and St Stephen)

Begun in 1030 under Conrad II, the triple-aisled vaulted basilica of red sandstone was influential in the development of Romanesque architecture during the 11th and 12th centuries, and is the largest Romanesque church. In 1981 it was added to the UNESCO World Heritage List. The red sandstone for the building came from the mountains of the Palatine Forest and is thought to have been shipped down the channelled Speyerbach.

It was nearly completed and consecrated in 1061. This phase of construction, called Speyer I, consists of Westwerk, nave with two aisles and an adjoining transept. The choir was flanked by two towers. The original apse was round inside but rectangular on the outside. The nave was covered with a flat wooden ceiling but the aisles were vaulted, making the cathedral the second largest vaulted building north of the Alps (after Aachen Cathedral). It is considered to be an outstanding example of early Salian architecture.