Raleigh–Durham International Airport, locally known by its IATA code RDU, is an international airport that serves Raleigh, Durham, and the surrounding Research Triangle region of North Carolina as its main airport. It is located in unincorporated Wake County, but is surrounded by the city of Raleigh to the north and east, and the towns of Cary and Morrisville to the south. The airport covers 5,000 acres (20 km2) and has three runways.