A short Thalys hop away from Cologne lays Brussels. As you know, Brussels is the capital of the European Union (EU) and probably of beer, too. No other country in the EU brews more different types of beers than the Belgians.
Derived from their long brewing tradition enrooted by the monks they have many different small, mid, and industry sized breweries all across their country. That means that there must be many beers to taste.