Warp Zone

"But this really is the most direct way. There should even be a warp zone coming right ahead of us!" "Let's do it!"

- Sonic the Hedgehog and Miles "Tails" Prower.

A Warp Zone (ワープゾーン Wāpuzōn) is a wormhole which allows various people to travel between locations. It is unexplained if it is hidden at random places or if it shows up at a certain time.

Welcome to Eggmanland
While in the Land of Darkness, Sonic and Tails are on their route to Robotropolis, but when doing so, they get chased by some badniks who attack them. Sonic is skeptic about Robotnik's route and thinks this is his doing, but Tails is convinced it is the correct way and also points out a warp zone in front of them. They speed at it and get transported in the wormhole. Sonic spins whilst Tails flies behind him, into the ancient city.