Chocolate Museum
You should definitely take a little visit to the Chocolate Museum in Cologne (Köln). It's a real pleasure. It is located on one of the islands in the Rhine river and it's very easy to get to. Once you're inside the museum, the smell of chocolate fills every room, and it's inside the museum where you can see how chocolate is made , i.e., the entire process from start to finish right up until those delicious Lindt chocolate bars are wrapped! You get to see how the machines pour the chocolate into molds, are cooled and then taken out of their molds. You can also see how tablets, etc, are made. Just in the place where you can watch the entire preparation process will find a huge chocolate fountain, where you can dip a cookie! Note that you can do that as many times as you want and pretend like you're an expert chocolate taster.