Poreč is almost 2,000 years old, and is based on a harbour protected from the sea by the small island of Sveti Nikola (Saint Nicholas). The city's population of approximately 12,000 resides mostly on the outskirts, while the Poreč region as a whole has a population of approximately 17,000 inhabitants. The city area covers 142 km², with the 37 km long shoreline stretching from the Mirna river near Novigrad-Cittanova to Funtana-Fontana and Vrsar-Orsera in the south.
The city plan still shows the ancient Roman Castrum structure. The main streets are Decumanus and Cardo Maximus, still preserved in their original ancient forms. Marafor is a Roman square with two temples attached. One of them, erected in the first century AD, is dedicated to the Roman god Neptune; its dimensions are 30 m by 11 m.

A few houses from the Romanesque period have been preserved and beautiful Venetian Gothic palaces can be seen here. Originally a Gothic Franciscan church built in the 13th century, the 'Dieta Istriana' hall was remodeled in the Baroque style in the 18th century.

The Euphrasian Basilica, rebuilt in the 6th century under the Byzantine Empire and bishop Euphrasius, is the most important historical site in Poreč. It is a protected World Heritage Site, so designated by UNESCO in 1997.

Between the 12th and 19th centuries, the city had defensive walls, as the better-known Dubrovnik still does today.