Join Date: Aug 2006
Location: MUC (home), DUS (office), XXX (customer)
Programs: LH, AB, SPG, CC, Sixt, EC
Posts: 6,332
The problem is the Cologne Trade Fair is nearby the central station so as soon as there's a fair in town, all hotels are occupied.
During the period of time you are in Cologne, there's a "Dental Show" which might not be a big thing but it takes some hundred hotel rooms as well.
As I used to live nearby I am not really good in hotels because I always stayed home... Sorry!