Located on the Danube River, the Old Town of Regensburg with Stadtamhof is an exceptional example of a central-European medieval trading centre, which illustrates an interchange of cultural and architectural influences. A notable number of buildings of outstanding quality testify to its political, religious, and economic significance from the 9th century. The historic fabric reflects some two millennia of structural continuity and includes ancient Roman, Romanesque, and Gothic buildings. Regensburg’s 11th- to 13th-century architecture still defines the character of the town marked by tall buildings, dark and narrow lanes, and strong fortifications. The buildings include medieval patrician houses and towers, a large number of churches and monastic ensembles as well as the 12th-century Stone Bridge. The town is also remarkable as a meeting place of general assemblies until the 19th century. Numerous buildings testify to its history as one of the centres of the Holy Roman Empire.