I often mention being at the ol' Imperial Palace. Some might think this is a flight of fancy, but it's the literal truth. I live in the ruins of a thousand year old Palace, built for an emperor.
Charlemagne built a palace here, one of eight, completed in 810 CE. While he's entombed at Aachen, and rarely visited here, some sources indicate that Ingelheim, with it's vineyards and bee gardens, was his favorite. I occasionally encounter his ghost. (He loves today's high octane weed, the cannabis in his day was "not like this!")
The Aula Regia (Throne Room) is "right across the street".
When the Palace was built, there was a small private chapel, and church services were held at St Remegius (est ca 740 CE, still active) The Palace Church, which is also "right across the street", wasn't added until the late 900s.
The defensive walls were added in the 1100s by Emperor Friedrich I Barbarossa. We live in the courtyard formed by the defensive walls.