For all cities with a population greater than one million, Frankfurt is closest to Cologne and farthest from Auckland. The closest foreign city is Prague and the farthest domestic city is Berlin. See below for the top 5 closest and farthest cities (domestically, internationally and by continent) and to see which cities, if any, Frankfurt is the closest and farthest to. Filter to include all cities over 100k, 500k or 1 million in population.