What to See
A must see for this place is the Dom/Church of Cologne. Inside this church is the believed reminisce of the Three Magi. It is a glass case and inside the glass case is a gold case and inside the gold case are the reminisce. They have Cathloic service here on Sunday mornings, and they like to pay homage to what is inside this case. While you are here make sure to take a trip up the 700+ stair trip to the very top of the tower! It is well worth the trip, because you will have one very good view of the city up there. Be sure you get a good meal in you before you attempt this feet though, because your legs will get very fatigued. Have fun and keep traveling!
What to Eat
Kolsh is a light, pale, sweet beer (not very bitter) brewed only in Cologne. I was told that you used to be able to call yourself a Kolsh if from your brewery you could see the Dom Cathedral. Interesting tidbit. There are a few companies that still brew it. Make sure to try it while in Cologne!