Dia (), also Diospolis (Διόσπολις), was a port city of
ancient Bithynia
Bithynia (; ) was an ancient region, kingdom and Roman province in the northwest of Asia Minor (present-day Turkey), adjoining the Sea of Marmara, the Bosporus, and the Black Sea. It bordered Mysia to the southwest, Paphlagonia to the northeast a ...
on the
Pontus Euxinus
The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
in
Asia Minor
Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...
.
Marcian of Heraclea
Marcian of Heraclea (, ''Markianòs Hērakleṓtēs''; ; fl. century AD) was a minor Greek geographer from Heraclea Pontica in Late Antiquity.
His known works are:
*'' Periplus of the Outer Sea'' (Greek: ''Περιπλοισ τησ εΞω Θ ...
Hypius Hypius or Hypios (), also Hyppius or Hyppios (Ὕππιος), was a river of ancient Bithynia, not far westward from the Sangarius River. The river itself is very small; but at its mouth it is so broad that the greater part of the fleet of Mithridat ...
, which river is between the
Sangarius River
The Sakarya (; ; ; ) is the third longest river in Turkey. It runs through the region known in ancient times as Phrygia. It was considered one of the principal rivers of Asia Minor (Anatolia) in Greek classical antiquity, and is mentioned in th ...
and
Heraclea Pontica
Heraclea Pontica (; ; , ), known in Byzantine and later times as Pontoheraclea (), was an ancient city on the coast of Bithynia in Asia Minor, at the mouth of the river Lycus. The site is now the location of the modern city Karadeniz Ereğli, in ...
. The name in Marcian, Diaspolis (Δίας πόλις), may be a mistake for Diospolis, which
Ptolemy
Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzant ...
has. There are some very rare coins with the epigraph ''Dias'' (Διας), which Sestini assigns to this place.
Its site is located near
Akçakoca
Akçakoca is a town in Düzce Province, in the West Black Sea Region of Turkey, located about 200 km east of Istanbul. It is the seat of Akçakoca District.Asiatic Turkey.