One of the most interesting beer cities in the world is Cologne, Germany. It has its own beer style, kölsch, but that only begins to express things. For the most part, Cologne only has kölsch. Coming on 30 years ago, the local breweries got together and decided to define kölsch. According to the Kölsch Konvention of 1985, the beer must be a pale, top-fermented beer. It must be “hop-accented” and filtered, brewed within a gravity range of 11º to 14º Plato (1.044 – 1.053). Finally, it must be served in a 20 cl cylindrical stange glass. Now, when you stop into a pub, that's what you get. It's possible to find other beer, but the ubiquity of the local pale ale is astounding. Keep in mind that this is a modern European city, and there's nothing making the locals fall in line and drink just this one style of beer--except tradition and pride.
When you go to a pub in Cologne, a waiter will strafe your table carrying a tray of glass vials by a sturdy handle. If you have no beer, he'll ask if you wish one and plunk a glass in front of you and make a tick mark on your coaster. If you already have a glass, but it's getting low, he'll plunk a glass on your table and tick the coaster. In only rare circumstances will you have to crane your neck to look for a waiter for a refill (in three days in the city, it never happened to me).
Next weekend, from 11 am to 9 pm, Prost! (4237 N Mississippi Ave) becomes a little enclave of Cologne, replete with three varieties of German kölsch, stange glasses, and proper trays. If a trip to Germany is not in your immediate plans, I recommend stopping in to get a flavor of authentic Cologne culture.