Doctor Eggman's Fortress

As the name suggests, this location (mistakenly referred to as "Chaos Control" in the English version) serves as Doctor Eggman's base of operations for the first 13 episodes of Sonic X until it got destroyed by the President's order.

Description
This structure is mostly a tall blue-colored circular tower with horizontal lines. A yellow, rounded roof stands on top of it with multi-colored lights directly below it and an antenna standing on it. The interior of the base mainly has circular corridors. Deep within the base has a generator room where it controls the base's main power systems.

History
In the first episode "Chaos Control Freaks", the interior of the base was first seen as Eggman plans to utilize the energy of the Chaos Emeralds he collected to activate a machine in the center of the room while holding Cream and Cheese hostage. However Sonic busts his way through the robots that are attempting to repel him from entering the base and smashes his way to the room where Eggman is. A fight later ensues between one of Eggman's robots and the hedgehog but the robot shoots down the machine in the center causing Chaos Control, warping everyone and the base to Earth through time and space.

The base was located in an unnamed island in the Southern Sea, distant from the human civilization but Eggman plans to conquer the world. He sends in his robots from his base but every time they are destroyed by the heroic efforts of Sonic and his friends. This however concerned the President, who considers Eggman a big problem to the human society and resorts to taking action and finding a solution to destroy the base. In episode 11, "Fly Spy", he and his advisors decide to send in G.U.N's two agents, Topaz and Rouge the Bat, to infiltrate the base. Despite this, Rouge engaged a fight with E-70 Noizi and destroys it with Topaz's help, escaping with Topaz to safety.

During the following two episodes, the military decides to plan a large scale attack at the base with most of their arsenal keeping the base's defenses focusing their attacks on them while sneakily sending a special force led by Rouge and Topaz to destroy the generator room they've discovered earlier. Dr. Eggman is out on an errand during the majority of the fighting, making this operation slightly easier. Knuckles joins with the G.U.N special force to help them locate the generator room. Eventually they found the generator room and begin to plant explosives around but as soon as the explosives start counting down, they are locked in the generator room, into their impending doom. Dr. Eggman returns only to witness the fighting before hopping into the base to destroy the X-Tornado but the heroes avoided, sending Sonic into the base to find the doctor. Meanwhile, Knuckles and Rouge attempt to bust through the door in order to escape although they are not having any luck on doing so. Sonic finally confronts the doctor in his new powerful robot, "E-18 Guerra-Hard" which is powered by 2 Chaos Emeralds. Sonic is greatly overwhelmed by the robots powers but manages to defeat it and regains the Emeralds and using their powers, he smashes through the base while freeing Knuckles, Rouge and the G.U.N forces. Finally the bombs finally detonate, destroying the base for good while it explodes in flames but everyone escaped unharmed as the citizens cheer of their victory.