The sanctuary of Apollo Actius at this promontory predates the battle by centuries. It was probably founded by the Corinthian colonists of Anactorium — the settlement whose name, Anactorium, may itself derive from the same root as Actium. In the 3rd century BC, the Acarnanians took control of the sanctuary, and the chief priest of Apollo became important enough that his name was used to date official documents, like the first Archon at Athens. There was a festival here too, the Actia, celebrated in Apollo's honor with athletic and musical contests. Strabo describes the temple standing on an eminence above a grove of trees, with a harbor below. Pearl fisheries operated off the cape, noted by Pliny. It was a working sacred precinct at a strategic maritime location — which is why, when two Roman warlords needed to stage their confrontation, they chose this particular stretch of water.

Mark Antony and Cleopatra had been bottled up in the Ambracian Gulf for months before the battle, their fleet and army weakened by blockade, disease, and defections. Octavian's admiral Marcus Agrippa had cut off their supply lines and seized key positions along the coast. When Antony finally forced a naval engagement on 2 September, his roughly 500 ships faced Octavian's approximately 400. The numbers favored Antony, but Agrippa's lighter, faster vessels — Liburnian galleys — outmaneuvered Antony's heavier quinqueremes. During the battle, Cleopatra's squadron of 60 Egyptian ships broke through and fled south toward Egypt. Antony followed with a small escort, abandoning his fleet and his army. More than 5,000 of his sailors and soldiers died in the battle and its immediate aftermath; some 250 ships were sunk or captured. The men and women Antony left behind — tens of thousands of them — had no choice but to surrender. Octavian was 31 years old. He now controlled the Roman world.

Octavian did not leave the site to silence. He enlarged the Temple of Apollo and revived the Actia festival on a grander scale, making it a quinquennial celebration — held every five years — with musical contests, gymnastics, and horse races, elevated to the rank of the great Panhellenic games. Directly across the channel on the Epirus shore, he founded a new city: Nicopolis, City of Victory, populated partly by inhabitants relocated from nearby towns including several in Acarnania. The promontory of Actium became a kind of suburb of Nicopolis. Augustus shaped the memory of the battle with the same deliberateness he brought to everything else. The victory at Actium was the founding event of the Principate, and he made sure the landscape said so.

In October 1980, the Greek Ministry of Transport announced that shipwrecks from the battle had been located near the entrance to the Ambracian Gulf — the physical residue of the engagement, lying in the sediment. In the summer of 2009, archaeologists excavating the ruins of the Temple of Apollo found two statue heads: one of Apollo, one of Artemis. The Aktio-Preveza Undersea Tunnel, completed in 2002, now connects the promontory to Preveza on the far shore — 1,570 meters total, of which 909 meters run beneath the channel. The airport, LGPZ Aktion National Airport, operates on the flat ground of the cape. History here is layered under asphalt and saltwater, but it has not entirely disappeared.