Corinth, Tartarus

Ephyra (aka Corinth)
Most of Sisyphus's evil deeds take place in a town called Ephyra. Some say that Sisyphus founded this ancient city that became the city-state of Corinth, which is situated on the isthmus that connects the Peloponnesian peninsula with the mainland of Greece. Among many other things, Corinth is also the place where Medea is said to have killed her and Jason's children.

Tartarus
Though Sisyphus escapes this deepest pit of the Underworld at first, he eventually ends up there again. It's in this awful place that he must forever push his rock up the hill. Tartarus is kind of like the maximum-security prison of the Land of the Dead. It's the place where all the hardcore criminals are sent. Other famous inmates include Tantalus, Ixion, and the Titans.