Arcedian Sea
The Arcedian Sea is one of Arden's major seas. It waters the coasts of Boréa, Northern Messenia, north-eastern Ascesia, and Diothún. The Arcedian connects to the Prothenian Ocean through the Marche-Laberse Strait (in the Onnech Sound). The boundary between the Arcedian and Medius Sea is traditionally the line from Árakan (in Messenia) to Sarbatia (in Ascesia). To the north, the line between the northwestern tip of Boréa to the island of Diothún marks the boundary with the Arctic Sea.
The sea's name originates from the Sabāmanians: it is named after the Arcedii, a tribal group (likely related to early Ternian peoples) which lived in what is modern Quènie. The Quèno-Dordanian region of Arcedia on the eastern littoral of the Quenian Peninsula is also named after them.