The geographer Strabo noted that Parium was a colony of three cities: Milesian traders, Erythraean sailors, and settlers from the island of Paros all had a hand in building it. That coalition of founders suggests a city conceived as a commercial venture from the start. By the Roman period it had grown into a colonia with two working harbors, positioned to intercept all goods moving toward what would become Istanbul. Every amphora of Aegean wine, every bolt of Anatolian cloth bound for the Bosphorus had to pass Parium's customs station first. The city became wealthy enough to mint its own coinage in abundance — ancient coins of Parium are comparatively common today, attesting to the scale of its commercial output. From at least the Archaic period onward, the city used the Gorgoneion, the face of Medusa, as its badge on coins — a fierce emblem for a city accustomed to guarding a narrow passage.

Few cities in the ancient world changed allegiance as often as Parium — and survived each transition. It belonged at one point to the Achaemenid Persian Empire; Herophantus served as tyrant of Parion under Darius I, governing in the name of a king whose palace lay a thousand miles to the east. Then came membership in the Delian League under Athenian leadership, then absorption into the domain of Lysimachus, one of Alexander the Great's successor generals, and then rule by the Attalid dynasty of Pergamon. The Romans finally incorporated it as a colonia within the province of Asia. When that province was subdivided in the fourth century, Parium found itself in the province of Hellespontus — still on the same cape, still watching the same water, but flying yet another administrative banner. The city's ability to persist through all of it speaks to the enduring value of geography.

Christianity reached Parium early. The Acts of the martyr St. Onesiphorus establish that a Christian community existed there before 180 AD. Over the following centuries the city produced a roster of saints: Menignus, martyred under the emperor Decius and venerated on 22 November; Theogenes, bishop and martyr, remembered on 3 January; Basil the Confessor, bishop and martyr in the eighth century, honored on 12 April. The church historian Le Quien counted fourteen bishops of Parium across the medieval period, the last living in the mid-fourteenth century. By 640 the see had become an autocephalous archdiocese — answerable to no higher authority — and it held that independence until the Emperor Andronicus II Palaeologus elevated it to a metropolis in the late thirteenth century under the combined title of Pegon kai Pariou. The see was suppressed in 1354. Today it survives only as a titular see of the Catholic Church, a name assigned to bishops who hold an ancient title without a living congregation.

Archaeologists began systematic work at the Parium site in 2005, in the village of Kemer near the town of Biga in Çanakkale province. The finds span the full sweep of the city's life. Sarcophagi and ancient artifacts have emerged steadily, but the discoveries that carry the most human weight are smaller. In 2017, excavators found ancient toys inside children's tombs from the Hellenistic period — miniature objects placed beside the young dead to accompany them into the afterlife. Near the same necropolis they found a baby bottle. Those objects, more than the coin hoards or the architectural remains, close the distance between the ancient city and the present: parents here buried their children with the same tender, heartbroken logic parents have always followed. Strabo also wrote of a monumental altar at Parium with sides the length of a stadion, sometimes placed among the wonders of the ancient world, though no archaeological evidence of it has yet emerged.

In the Ottoman period the ruins of Parium lay at the Greek village of Kamares — a name meaning 'the vaults,' a memory of standing arches — on the small cape called Tersana-Bournou. Today the site is accessible near Kemer on the south shore of the Sea of Marmara, where farmland and scattered stones mark what was once a city of two harbors and abundant coin. The cape still juts into the water. Ships still pass. The customs house is long gone, but the geography that made Parium matter has not changed at all.