Beneath buildings, meters of earth, stone, and rubble, lie yet undiscovered testimonies to Cologne's approximately 2000-year-old city history, when it was known as Colonia Claudia Ara Agrippinensium. These remnants still come to light during construction work, even after centuries – such as in 1941, when the famous Dionysus Mosaic with its 1.5 million tiles was discovered. Or in 2023 at Neumarkt, when archaeologists working in the field of archaeology unearthed a Roman bathing complex. Some of these you can visit underground or in museums, while others are partially preserved above ground – like the old city wall, gates, or towers. Cologne remained Roman until the 5th century and still has many stories to tell you from these long-gone centuries.