The gates of underworld in Aeneid?

In Virgil's Aeneid, the gates of the underworld are described as being made of iron and guarded by the fearsome three-headed dog Cerberus. The gates are said to be located in a dark cave at the edge of the underworld, and they are only opened to allow the souls of the dead to enter. The gates are also said to be inscribed with the words "Abandon all hope, ye who enter here," warning those who pass through them of the horrors that await them in the underworld.

Tartarus