Poreč was the Roman colony of Parentium, a town built on a small peninsula on the west coast of Istria, and
its old town still follows the Roman grid: the main streets are the ancient Decumanus and Cardo, and the
remains of temples stand on Marafor, a Roman square. Its great monument, though, is later — the
6th-century Euphrasian Basilica.
What is there today
The town plan still shows the shape of the Roman castrum, and the two main streets, the Decumanus and the Cardo
Maximus, keep their original lines. Marafor is a Roman square with
two temples attached to it; one, built in the 1st century AD and about 30 by 11 m, was dedicated to Neptune
(en.wikipedia). What is visible today are fragments: column shafts and the ruined corner of a temple podium among
the houses (the photographs).
The one stop with its own page is the Euphrasian Basilica, the 6th-century cathedral with its famous apse
mosaics, whose predecessors began as a house church in the Roman town (the parish).
Is it worth the trip?
For the basilica, yes. For Roman Parentium on its own, no: walking the Decumanus is a pleasure, and it is good to
know you are on a Roman street, but the Roman remains amount to a few temple fragments. Treat the Roman town as the
setting for the basilica rather than a destination in itself.
History
A Roman castrum was built in the 2nd century BC on the small peninsula, about 400 by 200 m, where the town
centre now stands. Under Augustus the settlement
became a town and part of the colony of Colonia Iulia Parentium (en.wikipedia); Pleiades records it becoming an
oppidum of Roman citizens, then a municipium under Augustus, and a colony under Tiberius. A Christian community was
organised here by the 3rd century, and its first bishop, Maurus, was martyred (the parish; en.wikipedia). After 476
the town was held by the Ostrogoths, and from 539 it belonged to the Byzantine Empire, under which the Euphrasian
Basilica was built (en.wikipedia).