…that the impressive Bridge Gate on the town side of the Inn underneath the Residence was also the Bridge Head in the 12th century?

Built by the Prince Bishop of the time in the year 1143 because of the increasing traffic volume over the Inn: Pilgrims on their way to the Holy Land! In order to have absolute control he built the Bridge Head into the Residence.
The high arch on the façade shows where the drawbridge once was.