now the Maritza, the largest river in Thrace, rises in the high ground between Mounts Seonius and Rhodope. It flows in a S.E. direction from its source to Hadrianople; from that city to the sea its course is almost due S. It falls into the Aegean nearly opposite the island of Samothrace, and forming at its mouth the Palus Sten-toria. Unlike most of the rivers in Greece the Hebrus is navigable for about two-thirds of its course. Small craft sail up as far as Philippopolis. Its principal tributaries are the Artiscus (Bujuk-dere), the Agrianes (Ergene), Contadesus (Saradjala), and Tearus (Tekodere). It was at the source of the Hebrus that Darius erected a pillar with an inscription to the effect that its waters were the purest and best, just as he himself was the fairest of men.