It was built in the Hellenistic period in Magna Graecia by King Hiero II and is the largest altar known from antiquity.

[2] There were stairways on the eastern side of the altar at the northern and southern ends, which led up to the lower level of the structure.

Below the structure, on the eastern side, there was a natural grotto, about 18 metres deep which contained votive offerings, some of which were deposited in the Archaic and Classical periods, long before the altar was built.

[2] To the west of the altar there was a rectangular open space with a water-proofed basin in the centre, surrounded by a u-shaped stoa.

Stylistic analysis of the sculptural fragments from the altar confirms this, showing that they were made at the same time as the third phase of the nearby Greek theatre, which belongs after 235 BC.

The votive deposit in the natural grotto under the eastern side of the altar shows that the area was already a sacred site in the Archaic period, not long after the city of Syracuse was established.

[2] Other suggestions, not necessarily mutually exclusive, are that the altar, as well as the nearby theatre, played a role in meetings of the League of the Sicilians which was placed under Hiero's control after the First Punic War,[4] or that it was built for the five hundredth anniversary of Syracuse's foundation.

[2][5] From late antiquity onwards, the altar was quarried away as raw material for other structures in Syracuse, most recently for the Spanish fortifications of Ortygia at the beginning of the fifteenth century.