Cologne's cathedral is the first thing you notice and the last thing you forget. The twin spires climb a hundred and fifty-seven metres above the Rhine, and the building took more than six hundred years, from 1248 to 1880, to finish, a scale of ambition that still feels slightly absurd. It survived the bombing of the Second World War, which flattened much of the surrounding city, and the sight of the black Gothic stone rising out of postwar rubble in old photographs is one of the great images of the period. Climb the tower if your knees allow; the view is the best in the city.
The city is much older than the cathedral. The Romans founded a colony here in the first century and named it after the emperor's wife Agrippina, and the word Colonia is the origin of the name Cologne. The Römisch-Germanisches Museum next to the cathedral shows a huge Roman mosaic where it was found. Cologne is also a city of beer and carnival. Kölsch, a pale, light beer served in tall thin glasses, is the only thing you should order in the brewery pubs of the old town, and the arrival of a new glass is automatic until you place your coaster on top.
The riding starts, like most big-city starts, with a bit of patience. The Rhine splits the city, and the bridges, such as the Hohenzollern railway bridge with its thousands of padlocks, can be congested at rush hour. Low-emission zones, one-way streets and tram lines are the order of the day. Once you are out of the urban area, the Kottenforst and the Eifel to the south give the best escape, with forest roads, gentle hills and quiet villages, and the Siebengebirge on the far side of the Rhine has some lovely twisty roads.
Fuel and food are no problem in a city of nearly a million people, with stations on every main road and bakeries at every corner. Weekdays are best for the way out, since the weekend brings visitors and local cyclists in numbers. The smell of the city is a mix of river, brewery and traffic. On a clear morning the light behind the cathedral is a good moment for a photograph before you roll away.