Tourism in Greece traces its roots to ancient times. Cultural exchange took place between the Greek colonies of Magna Graeca and the young Roman Republic before Rome's rise to dominance of the Western Mediterranean. When Greece was annexed by the Roman Empire centuries later, the cultural exchange that started between the two civilizations triggered as a result a large number of ancient Roman tourists visiting the famous centers of Greek philosophy and science, such as Athens, Corinth and Thebes, partly because Greece had become a province of the Roman Empire and Greeks were granted Roman citizenship.