15. International Airport Old Mariscal Sucre, Ecuador. It was a real nightmare even for the most highly skilled pilots. The airport was located at a high altitude, in the heart of the densely populated capital of Ecuador, which greatly increased the risk factor. The mountainous terrain, active volcanoes and the valley, which was constantly tightened by fog, made it difficult to land and take off at this airport. But that’s not all: the runway was uneven, it had a large number of bumps. Fortunately, the airport was closed last year and rebuilt.