Cologne (German: Köln, Ripuarian: Kölle) is a city on the Rhine river in North Rhine-Westphalia. It is the fourth largest city in Germany with around one million residents. It is one of the nation's media, tourism and business hotspots, and is considered one of the most liberal cities in Germany.
Cologne has a rich history, reaching back to the time of the ancient Roman Empire, when it was founded. It has remained a constantly inhabited important regional centre since. Compared to other German and European cities, the ancient and medieval Cologne was relatively large, covering most of the modern-day city centre. A wealth of architectural heritage can therefore be found across the city ranging from pre-Christian times to strikingly modern buildings, with a high concentration of Romanesque and Gothic architecture, culminating in the magnificent cathedral (Dom).