Dr. Eggman's Lair is an island fortress neighboring Bygone Island in the Sonic Boom Zone. It is Dr. Eggman's residence, laboratory, and the launching point for his various conflicts with Sonic the Hedgehog and his allies.
Eggman retreated to his lair after the defeat of his Big Boy mech, only to be unexpectedly approached by Knuckles proposing an alliance. However, this later turned out to be a plot by Knuckles-albeit ill-planned-to help his friends defeat Eggman on their next engagement. Eggman promptly returned here to have the Big Boy repaired, only for Orbot and Cubot to become distracted by Amy Rose's Piko Hammer. As a result, Big Boy was not fully repaired and was later destroyed by the Piko Hammer, forcing Eggman to return to the lair for additional repairs. Unfortunately, after finally perfecting the Big Boy mech, it would be destroyed by the Rock of Justice, forcing Eggman to return home yet again. (SB: #1, #2, #3, #4)
Perhaps the most unusual visit that Sonic or any of his allies have paid to Eggman's Lair was made by Sticks the Badger following her meeting with the Maverick Hunters. After recruiting Comedy Chimp and Fastidious Beaver to her "Team Sticks," she led the robots of Earth 21XX to Eggman's lab in search of a means of opening up another Genesis Portal. Orbot and Cubot briefly opposed this effort, but were soon brought into line by Zero. (SB: #8)
- Eggman's lair is one of a number of Sonic Boom elements that doesn't originate from the game series; it first appeared in the cartoon.