A minimum of 2 stopovers must be taken on an a round the world airfare. More than 20 stopovers can be had on the top tier of tickets. A city may only be stopped in once but can be transited up to 3 times. Some tickets will restrict the number of stopovers in each continent, particularly the OneWorld® tickets which only allow 2 stops in Europe on their 26,000 mile around the world airfare.