In pictures: Previous Olympic Summer Games (16)

　　19th Olympic Summer Games,1968,Mexico City, Mexico

The choice of Mexico City to host the 1968 Olympic Games proved to be a controversial one because of the city's high altitude, 2,300m. The altitude proved an advantage in explosive events such as short-distance running, jumping, throwing and weightlifting. But the rarefied air proved disastrous for those competing in endurance events.