The Thyamis, also known as Glykys (Γλυκύς) or Kalamas (Καλαμάς), is a river in the Epirus region of Greece. It flows into the Ionian Sea. It is 115 km (71 mi) long, and its drainage area is about 1,800 km2 (690 sq mi), over 99% of which on Greek territory. The names of the Chameria region, as well as the Chams, derive from the river's name.

Chameria is a term used today mostly by Albanians to refer to parts of the coastal region of Epirus in southern Albania and Greece, traditionally associated with the Albanian ethnic subgroup of the Chams. For a brief period (1909-1912), three kazas were combined by the Ottomans into an administrative district called Çamlak sancak. Apart from geographic and ethnographic usages, in contemporary times within Albania the toponym has also acquired irredentist connotations. During the interwar period, the toponym was in common use and the official name of the area above the Acheron river in all Greek state documents. Today it is obsolete in Greek, surviving in some old folk songs. Most of what is called Chameria is divided between parts of the Greek regional units of Thesprotia, Preveza, and Ioannina ; and the municipality of Konispol at the southernmost extremity of Albania. As the wider Greek toponyms Epirus has existed since antiquity and the narrower Thesprotia also reflects an ancient name, and given the negative sentiments towards Albanian irredentism, the term is not used by the locals on the Greek side of the border.