The Aeneid was written by Vergil to serve as a national epic for Rome. As has likely been noted again and again, the Roman’s weren’t nearly as interested in abstract things as the Greeks, and hence, despite the required “visit the dead” scene, taken from the Odyssey, the Aeneid is relatively free of the underworld.
Still, considering that an entire book is taken up by this passage, it is worth noting, especially as in the Aeneid, the group actually enters the underworld, rather than in the Odyssey, where they merely summon various spirits.
The sacrifice is again performed and the sibyl tells them to pluck a golden branch from a tree (likely a white aspen) in order to be guided within. The underworld is then described, including descriptions of both Hades and Persephone.