The Porta Nigra (black gate) in Trier, Germany.

Trier

Coat of Arms of Trier

Trier is known as the oldest City of Germany. It was founded in the late-4th century BC as Treuorum. Therefore it is very famous for its Roman buildings and monuments like the Porta Nigra (black gate), the Roman bath, the Constantine Basilica but also for its cathedral, its palace and more.