After having consulted the Sibylline Books and gained a favourable response, a delegation of Roman elders was sent to Epidaurus in Greece, famous for its sanctuary to Asclepius, to obtain a statue of him to bring back to Rome.

The legend also relates that during the propitiatory rites a large serpent (one of the god's attributes) slithered from the sanctuary and hid in the Roman ship.

[2] As they were on the river Tiber and about to reach Rome, the snake crawled out of the ship and disappeared from sight on the island, marking the site where the temple was to be built.

The medieval well near the altar of the church seems to be the same as that used to draw water for the sick in the classical period as mentioned by Sextus Pompeius Festus, a 2nd-century Latin grammarian.

Little remains of the temple - some fragments of the obelisk are now held in Naples and Munich and some travertine blocks were re-used in modern buildings on the island, including a relief of the staff of Asclepius.