The Imperial Palace in Ingelheim was erected in the second half of the 8th century. Charlemagne chose Ingelheim in 787 as the location for his winter quarters, arriving there before Christmas and remaining there without interruption until the middle of 788. However the palace was not completed before completed before 814. It served Emperors and Kings as a residence and place for governance until the 11th century. From the buildings of the Imperial Palace impressive relics above ground are preserved today. The greater part of the complex remains as foundation under ground level and allows it to be the basis for archaeological excavations to reconstruct the entire system of buildings.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.