North Rhine-Westphalia is the largest federal state in Germany and a significant international economic center with developed modern technologies.
Its population is 18 million people. Its capital is Dusseldorf and it is one of the most highly industrialized areas in Europe.
May and September month climate is warm and sunny which is the best time to visit North Rhine-Westphalia.
Cologne is filled with many wonderful restaurants and a number of very interesting museums, particularly the German-Roman museum. There is plenty to do.
I have never met a nasty person in Cologne. Everyone seems freindly and helpful, not just in the shops but on the streets as well.