This is the Plan of Cathedral at Aix–la–Chapelle in Aachen, Germany. It is an example of Romanesque and Gothic architecture in Germany. It was built in AD 796. The scale is in feet. "With the exception of the church built at Trèves (There) by the empress Helena, of which small portions can still be traced in the cathedral, there are no remains of earlier date than the tomb–house built by Charlemagne at Aachen (Aix–la–Chapelle), which, though much restored in the 19th century, is still in good preservation. It consists [...] of an octagonal domed hall surrounded by aisles in two [stories], both vaulted; externally the structure is a polygon of sixteen sides, about 105 ft. in diameter, and it was preceded by a porch flanked by turrets."

Plan of Cathedral at Aix-la-Chapelle, AD 796

This is the Plan of Cathedral at Aix–la–Chapelle in Aachen, Germany. It is an example of…