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