Lava Reef (Archie)

Lava Reef Zone is a region on Angel Island consisting primarily of volcanic activity.

Repairing the Death Egg
After his defeat at the hands of Sonic and Tails in the skies above Launch Base Zone, Dr. Eggman's Death Egg crash landed once again on Angel Island, this time on top of the volcanic crater, Lava Reef Zone. He eventually obtained the Master Emerald from the Hidden Palace Zone during a battle between Sonic and Knuckles and used it as an energy source to fuel his Death Egg. His repaired flying fortress then took off into the sky with Sonic, Tails, and Knuckles in pursuit. (VG: S3aK, SU: #64)

Knuckles later passed through Lava Reef Zone to reach Hidden Palace Zone in pursuit of a fleeing EggRobo controlled by Dr. Julian Snively, Dr. Eggman's assistant, after multiple encounters on the island.