Koln Travel Guide

There are quite a few areas and places where you can party.
Altstadt is mainly for tourists. If you want to get drunk fast with fellow travellers you are most likely to meet them there. Peters Brauhaus provides good food and not so good beer, the Paeffgen Brauhaus vice versa.
Kwartier Lateng (Zulpicher Straße) is for students and young persons who want to drink and have a good time. Party and concerts also in the Prime Club/Luxor, the Blue Shell and the mtc.
Friesenviertel is for the more well-to-do people. Make sure to check out the Paeff (not to confuse with the Paeffgen!). Often there are quite good DJs at work.
Ehrenfeld is for students and more alternative folk. Lots of nice pubs, bars, clubs and more. The Underground, the Live Music Hall (rock, alternative), the Sensor Club (dance), the Art Theater (funk, Drum'n'Bass), the Sonic Ballroom (punk, indie) are must-sees when you are in Ehrenfeld.

Besides that there are a few cool clubs and classic bars. Schreckenskammer and Elektra in Altstadt-Nord, Gebäude 9 in Deutz, Westbahnhof, Tor 2 right next to the central station, Apropo in the Severinsviertel,.....

Check out the cathedral (just near the main train station), one of the most beautiful in Europe. The cathedral was once the tallest building in the world, and was one of the few structures to have escaped the destruction of World War 2. The chocolate museum, located about a kilometer (or half a mile) from the cathedral, is also a must see. Situated on a small island just off the bank of the river Rhine, the Imhoff Stollwerck Museum boasts its own miniature rain forest (contained within a green-house of sorts) and mandatory chocolate fountain - a dream come to life for any Willy Wonka fan!

If you go to Cologne, next to the historic and art sites that are well known, you should definitely go shopping! Cologne has huge shopping streets where all the world class brands are present. The sales last longer here than in the rest of Europe, so go around February!
Also, Cologne is a foodparadise. Not only the typical German food is present, but also alot of etnic food is to be found. Especially give the Mexican food a chance. There are a few Mexican restaurants in Cologne and I have tested and approved already two of them. If I'm not mistaken, one of them was on the Neumarkt, not 100% sure though.