Dating back from the 1st century BC, when the Romans built a military camp here, Nijmegen is the oldest city in the Netherlands. Past and present blend harmoniously in this city, historic buildings are interspersed with fine examples of modern architecture. Its main sight, the largely demolished Valkhof, is medieval. The Carolingian Chapel was built after Charlemagne's Palatine Chapel in Aachen (Germany) as a symbol of the importance of this city as one of the principal seats of the administration of the Holy Roman Empire. Other sites are the weighing house and St. Stephen's church.