aftantzoglou designed the first important public buildings of the new capital. In 1896 Athens hosted the first modern Olympic Games. During the 1920s a number of Greek refugees, expelled from Asia Minor after the Greco-Turkish War (1919-1922), swelled Athens's population; nevertheless it was most particularly following World War II, and from the 1950s and 1960s, that the population of the city exploded, and Athens experienced a gradual expansion.
In the 1980s it became evident that smog from factories and an ever increasing fleet of automobiles, as well as a lack of adequate free space due to congestion, had evolved into the city's most important challenge. A series of anti-pollution measures taken by the city's authorities in the 1990s, combined with a substantial improvement of the city's infrastructure (including the Attiki Odos motorway, the expansion of the Athens Metro, and the new Athens International Airport), considerably alleviated pollution and transformed Athens into a much more functional city. In 2004 Athens hosted the 2004 Summer Olympics
