The gates of hell are various places on the surface of the world that have acquired a legendary reputation for being entrances to the underworld. Often they are found in regions of unusual geological activity, particularly volcanic areas, or sometimes at lakes, caves or mountains.
Legends from both ancient Greece and Rome record stories of mortals who entered or were abducted into the netherworld through such gates. Aeneas visited the underworld, entering through a cave at the edge of Lake Avernus on the Bay of Naples. Hercules entered the Underworld from this same spot.
In the middle of the Roman Forum is another entrance, Lacus Curtius, where according to legend, a Roman soldier, named Curtius, bravely rode his horse into the entrance in a successful effort to close it, although both he and his horse perished in the deed.
Lerna lake was one of the entrances to the Underworld.
Odysseus visited the Underworld, entering through river Acheron in northwest Greece.
Orpheus traveled to the Greek underworld in search of Eurydice by entering a cave at Taenarum or Cape Tenaron on the southern tip of the Peloponnese.
Pluto's Gate, Ploutonion in Greek, Plutonium in Latin, in modern-day Turkey unearthed by Italian archaeologists is said to be the entry gate to the Underworld; it is linked to the Greco-Roman mythology and tradition.
Rivers Cocytus, Lethe, Phlegethon and Styx were also entrances to the Underworld.