Katerini is a city and municipality in northern Greece, the capital city of province of Pieria (regional unit) in Central Macedonia, Greece. It lies on the Pierian plain, between Mt. Olympus and the Thermaikos Gulf, at an altitude of 14 m. The municipal unit of Katerini has a population of 85,851 (according to the 2014 census) and it is the second most populous urban area at the Region of Macedonia after Thessaloniki. The close distance between two cities (68 km), has been beneficial for Katerini's development over recent years. Katerini is accessible from the main Thessaloniki–Athens highway GR-1/E75 (with the Katerini's South, East and North interchanges) and the Egnatia Odos to the north. It is served by Intercity, Proastiakos (Suburban Railway) and local trains on the main railway line from Athens to Thessaloniki and there is a comprehensive regional and national bus service with its hub in the city.