Copenhagen Airport is the busiest in Scandinavia, and one of the larger in Europe. It has 50.000 passengers a day, somewhat over 20 million a year. I know it well. I got to spend a lot of time there lately. For some reason, I always end up late when I pass trough Copenhagen, mostly severly late. I sometimes end up sitting around in Copenhagen, even at times when I wasn't planning to visit Denmark at all.