Köln (Cologne), is the 4th largest city in Germany. It was founded in the year 38 by the romans, and it has been declared an official Roman city in the year 50. The therm "Eau de Cologne" comes from this city; at the turn of the 18th century, Johan Maria Farina created a fragrance that was more subtle and dignified, compared to the sweet fragrances that were popular back in the day, he named it after his hometown. The name eventually became a household therm used to market frangrances such as this (subtle, and not very sweet).
Histrorically, Cologne, after being a Roman city, then a Holy-Roman Catholic center, it became a free Imperial City in the 15th century, it's main purpose being the trade. At the end of the 18th century it became a French city because of the Lunéville peace treaty after the war of 1800. It was a british city after the WW1 until 1926. After the WW2 it was in the FDR (obviously, being a western city). Today it is one of the most free-minded cities in Europe, it is the host of several festivals and of one of the biggest traid-fair-grouds (Koelnmesse) in the world, which hosts some of the biggest events in trading.
My visit to Cologne was for the Photokina Trade Show where i've enjoyed observing the latest in photography and imaging equipment.
My impression of Köln:
Nice city, crowded, lots to visit, not the most interesting place on earth, but definetly a must-visit, if not only for the great architecture and nice people, for a fair or two. Photokina 2010 is definitely on my calendar.
Don't know if this would suit everyone, but i've had alot of fun visiting the city on a bike i rented from near the train station (Radstation underneath the Hohenzollernbrücke).