The city expanded rapidly after World War II; by 1950 its population had grown to 175,000. Roads connecting Antananarivo to surrounding towns were expanded and paved. The first international airport was constructed at Arivonimamo,  outside the city; this was replaced in 1967 with Ivato International Airport approximately  from the city center. The University of Antananarivo was constructed in the Ankatso neighborhood and the Museum of Ethnology and Paleontology was also built. A city plan written in 1956 created suburban zones where large houses and gardens were established for the wealthy. In 1959, severe floods in ''la ville basse'' prompted the building of large scale embankments along the edges of the Betsimitatatra rice fields and the establishment of new ministerial complexes on newly drained land in the Anosy neighborhood.