The Gigan Mountains are a location in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. They are a mountain range on Mobius that contains a hidden temple. Within it was the long-hidden Key to Babylon Garden.
Using a book from the library of Soleanna, the Babylon Rogues located a hidden chamber within the Gigan Mountains. When they got there, the found the Key. However, removing the Key from its pedestal activated the chamber's guardian, Angelus, who delivered a warning against removing the key. While dangerous, the guardian turned out to be an elaborate hologram of sorts and the Rogues disabled it by destroying projectors set around the chamber. The tunnel to the chamber later collapsed, and the Rogues were then chased by the Battle Bird Armada across the mountain range.