The second largest city in the Netherlands, Rotterdam lies on both banks of the Nieuwe Maas, the tidal southern arm of the Rhine, where it's joined by the little River Rotte. It's also the world's largest port, home to the massive Europoort facility through which so much freight passes on its way to and from the continent. Although almost completely destroyed by German air attacks in 1940, central Rotterdam was energetically rebuilt after the war and re-planned with modern shopping streets, residential districts, and high-rises, making it one of the most modern and architecturally interesting cities in Europe. Despite it's modernity, the city dates back to medieval times and was already prosperous by the 13th century, when a dam was built to separate the Rotte from the Nieuwe Maas (hence the city's name). Rotterdam has also long been important as a cultural hub, its early prosperity leading to the birth of Rotterdam's most celebrated citizen, the humanist Erasmus, born here in 1467. Today, it's as popular for its vibrant entertainment options as it is for its many fine museums, splendid architecture, and maritime tourist attractions.