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