Oropus sat where the river Asopus finishes its run to the sea, on a maritime plain stretching some five miles along the shore. Low hills, a spur of the Diacrian range, separated it from the inland plain of Tanagra and gave the place its in-between character. By geography it belonged to Boeotia, the land at its back. By ambition it kept falling to Athens, the power across the water. Ships from Oropus crossed to Euboea from a wharf the Greeks called Skala, and it is along this coast, where the modern town of Skala Oropou now stands, that scholars place the original settlement, washed by the same gulf that carried its trade.

The list of Oropus's masters reads like a roll call of Greek power. Athens held it long before the Peloponnesian War; the Boeotians took it back in 412 BC. A decade later, after the Oropians fell to quarreling, the Boeotians actually moved the whole town seven stadia inland, away from the dangerous, contested sea. For sixty years it changed hands again and again, until Philip II of Macedon, fresh from crushing the Greek city-states at Chaeronea in 338 BC, simply handed it to Athens. Then came Cassander, then Antigonus's general Polemon, who expelled the Macedonian garrison and gave the town to the Boeotians once more. Possession was never settled because the town was never really anyone's; it was everyone's frontier.

Living on a border has a way of shaping a people, and the Oropians earned a reputation they could not shake. The geographer Dicaearchus called them notorious for their grasping exactions, the tolls and duties they levied on everything passing through their territory. It was the petty tyranny of the gatekeeper, the toll-taker who controls a chokepoint and knows it. The writer Aristotle noted that in his day the place even went by another name, Graea, an ancient Homeric title revived by the Athenians, who organized its territory as an Attic deme. A town with two names and many owners, Oropus collected tolls the way it collected rulers, endlessly.

For all its mercenary edge, Oropus guarded something genuinely sacred. In its territory stood the celebrated sanctuary of the hero Amphiaraus, a place of healing and prophecy set, as Livy described it, among fountains and rivers. Pilgrims came here to sleep within the precinct and receive their cures in dreams. Dicaearchus painted the road from Athens to Oropus as running through groves of fragrant bay trees toward the temple, a green and gentle approach to a holy place. That sanctuary, the Amphiareion, survives in ruins to this day, its theater and long stoa still legible in the quiet valley, the most lasting thing this restless border town ever produced.