Super 3 hr tour with English speaking guide that seemed to get us everywhere: Old Koeln, new Koeln,…read moregreen belt, Dom, touristy areas. Well organized, great bikes, friendly staff, good starting/ending location. Highly recommended.
PS: since Koeln is flat, this is an easy biking tour, for all ages. Helmets provided. Bring water, if desired. Half hour stop in middle.