After the world was reduced to just the castle, following an assault by the Heartless, it was named simply "Hollow Bastion". It regains its name in Kingdom Hearts II after Tron finds a record of it in the computer's database and shows everyone what the town looked like when it started out, causing everyone from the Radiant Garden to remember the name. This world was run by Ansem the Wise during Kingdom Hearts Birth by Sleep, Maleficent and the Heartless Ansem in Kingdom Hearts and the Hollow Bastion Restoration Committee in Kingdom Hearts II.
Terra arrives here looking for Vanitas, but only finds a swarm of Unversed in the town center. He then sees Master Xehanort walking down a street and follows him. Along the way he notices the wizard Merlin drop Pooh's storybook. Returning it to the wise elder, Terra learns the book has the power to unlock his full potential and that it is not truly Merlin's; it is kept by the wizard regardless. Leaving Merlin's house, Terra sees a giant Unversed fly away and follows it through the Fountain Court, onwards.
Aqua arrives here shortly after Terra's arrival, having followed him in the Lanes Between. She first meets Scrooge McDuck, who says he saw someone (Ventus) heading towards the castle. She runs to the castle, thinking he meant Terra, where she meets a young Kairi being attacked by the Unversed. Mickey then appears from the sky and the two protect the young girl together. They also sense the pure light from Kairi, but Mickey is called away by his Star Shard immediately after he proposes that he and Aqua team up. Kairi offers Aqua flowers as thanks for helping her, and Aqua places a spell on Kairi in order to protect her light should it ever be threatened. Kairi's Grandma arrives and tells her story of the origin of light to Kairi as they head home. Aqua then sees a giant Unversed and chases it through town.
Ven, meanwhile appeared in Radiant Garden after Mickey's Star Fragment sent him there, however he sees Mickey walking towards the castle and follows him to the front doors, but the guards, Dilan and Aeleus prevent his entrance. But a giant Unversed appears, causing Ven to chase after it. The guards prepare to follow, but are reprimanded by Even, who says that the boy can take care of himself and also senses that Ven has no darkness in his heart, or rather it was taken out. In the town square, Ven defends Scrooge McDuck from the Unversed so the mister offers him three lifetime passports to Disney Town. Ven thanks him and runs after the Unversed, meeting Merlin along the way.
All three heroes arrive at the Reactor, chasing their respective Unversed. They are surprised to see each other, but first defeat the Trinity Armor that forms. They fight together and win. Ven shares his tickets to Disney Town with his friends. Ven tells of his journey and how he even defeated a masked boy who bad mouthed Terra. Terra knows this is Vanitas and bids him to go home with Aqua. Aqua wonders if Terra has gotten too close to the darkness. Terra is insulted and feels that Eraqus sent her to spy on him. As Terra leaves to follow his own path, Ven displays disbelief to Aqua's claims and goes after Terra, but not before telling a disheartened Aqua that she has changed.
Terra enters the lower portions of the Aqueduct, where he meets Braig, who openly tells him that he has captured Master Xehanort. Terra goes underground to the Purification Faclity to find the last person he trusts, but is approached again by Braig who wants the Keyblade for himself. The two battle, with the captured Xehanort imploring Terra to give into his darkness. Terra eventually does so, and shoots a burst of dark energy that hits Braig's face, giving the scars he appears with later and blinding one of his eyes. Terra and Xehanort form a pact to work together to destroy Vanitas. Terra then prepares to leave, even after Ven wants to come with him.
Aqua, meanwhile, left towards the town square, meeting Merlin on the way. In the town square, she meets Vanitas, who taunts her by inquiring about Ventus and then attacks. Aqua wins the battle, but Vanitas escapes, complementing her on her skill, and making an ambiguous comment that she'll be his "Plan B" and finishes by telling her only to get stronger. Ven then arrives, wanting to go with her as well, but Aqua declines and tells him just to go home, she then leaves.
Ven, after the battle with the Trinity Armor, passes by young Ienzo, being attacked by Unversed. He helps the boy as Even arrives. The scientist thanks Ven for rescuing the orphan, and also notes that they may be connected in the future. He plays with Terra's old wooden Keyblade, but drops in front of two teenagers, Lea and Isa. Lea challenges Ven, but loses embarrassingly. Isa says it is time that they left, with Lea saying that he and Ven will meet again someday because they are friends now. Isa has no clue as to why Lea is so friendly, but Lea responds he wants to be a part of many people's memories so that he can live forever in the memories of all the people he meets. The two look towards the castle, silently getting ready to do something, they then leave. Reminded of his friends, Ven leaves for new worlds.
In the last chapter, Aqua comes to Radiant Garden looking for Terra after creating Castle Oblivion. She finds Terra, however possessed by Master Xehanort's dark heart. Aqua struggles when he tries to strangle her, but she tries to make him remember his true self. Terra cannot overpower Xehanort's heart, leaving Aqua no choice but to battle her friend. Terra awakens the darkness in his heart in the form of the Guardian Heartless. However Aqua proves victorious, and Terra tries to release the darkness in his heart by sending himself to the Realm of Darkness. Aqua jumps in after him wearing her armor as protection. Unfortunately, Aqua realizes cannot save both of them, so she gives Terra her armor and Keyblade to protect him, and sends him back to the Realm of Light, while she stays in the darkness.
Terra's unconscious body is found in Radiant Garden the next morning by Braig, who brings Ansem the Wise and Dilan to retrieve the stranger. Terra can only remember the name, Xehanort, causing Braig to smile deviously. They also find Aqua's armor and Keyblade although they are unsure of what it is. Later, Terra, now using the name "Xehanort", has become Ansem's apprentice, and making an ally in Braig. Ansem and Ienzo then walk by, catching the boy's attention and the scientist's suspicion.
During the end credits, Lea and Isa are seen getting thrown out of the castle by Dilan and Aeleus. Later, Lea buys two sticks of Sea-salt ice cream from Scrooge McDuck and shares it with Isa. Kairi is also seen picking flowers and gazing up at the sky above her, while her necklace faintly glows.
Between Kingdom Hearts Birth by Sleep and Kingdom Hearts
Hollow Bastion was once a glorious castle towering over the Radiant Garden and owned by a respectful king, Ansem the Wise. Much of the history of the castle is unknown, other than that Ansem ruled from it. However, eventually Ansem's apprentices led by Xehanort overthrew their former mentor, and remodeled the castle to include mechanical components. The result was a twisted bastion; half beautiful castle, half distorted factory. According to Leon, Maleficent invaded Hollow Bastion's world with her Heartless nine years before the events of Kingdom Hearts. However, there were Heartless created by Xehanort during the time before, which may have escaped their imprisonment in the dungeons prior to Maleficent's arrival. Some residents managed to escape, many of whom ended up in Traverse Town. However, the youngest known resident, Kairi, was sent into the oceans of the worlds by Xehanort and ended up in Destiny Islands. During her reign in the castle as one of the false Ansem's minions, it is probable that Maleficent either created or remodeled the castle's keep, which has decorations and models of roses and her thorned plants.
- Main article: Hollow Bastion
Sora and his friends reunite with Leon, Yuffie, Aerith, and Cid, who have started the Hollow Bastion Restoration Committee, an organization attempting to rebuild the world that they once lived in. After reuniting with Merlin as well, Leon makes Sora, Donald, and Goofy honorary members of the committee and takes them to view the restoration work on the Bailey. There, after a surprise attack, the party has their first real encounter with Organization XIII in the form of taunts and cryptic messages. After unlocking the pathway to other worlds via his committee card, Sora heads out to search for King Mickey and Riku.
The party returns briefly to visit and assist Merlin, who has found Pooh's book, the entrance to the 100 Acre Wood. However, a raid by Heartless damages the book when they try to steal it from Sora's group, leading to Pooh's amnesia and the search for the book's Torn Pages.
When the party is called again to Hollow Bastion, they reunite with Cloud, who vows to go after Sephiroth. They then are sent by Cid and Merlin to assist Leon in the Bastion itself; along the way, they meet the Gullwings for the first time. After reaching the Bastion, they first see Ansem's study and are introduced to his seemingly malfunctioning computer system after a brief encounter with Tifa. After an unplanned trip to the Space Paranoids courtesy of Stitch, they finally meet with the King in Ansem's study, who promises to talk after they finish helping Tron. Sora and his party copy Tron's scrambled data, finding out about Ansem the Wise.
Mickey explains about Ansem the Wise, his impostor, and the Heartless and Nobodies that resulted, most notably Xemnas. While he explains many things to them, Sora learns that the King can't tell him about Riku. He charges them to go find the missing Riku and Kairi, but there is a sudden explosion outside the Bastion. Heartless and Nobodies begin pouring through a hole blown in the outer wall. Sora's party encounter Maleficent, who orders her Heartless to attack, and the Gullwings, who they trick into joining Leon's side. They also find Sephiroth, looking to fight Cloud.
The party makes their way to the Bailey, where they witness the Hollow Bastion Restoration Committee, the Gullwings, Cloud, and Tifa's attempts to stop the Heartless, as well as an encounter between Cloud and Sephiroth. Mickey orders them to find Riku and Kairi instead of fighting the Heartless, but Sora refuses and leaps into the fray, joined by Donald and Goofy. Their first encounter is with Demyx, who attempts to eliminate Sora again. They defeat Demyx, and Mickey catches up with them and admits his earlier decision was hasty. An explosion caused by a Heartless causes a boulder to fly at Mickey, but Goofy takes the blow instead and is seemingly killed. Spurred on by his sacrifice, the three jump into the battle, assisted by the other residents of Hollow Bastion. After a short time, it is revealed that Goofy is alright and reunites with them. Together, they work to halt the Heartless invasion.
They are triumphant in the end, but are confronted by Xemnas and Saïx who reveals, with help from Axel, Organization XIII's master plot is to form a Kingdom Hearts out of the hearts released from the Heartless that Sora slays with the Keyblade. Maleficent appears, attempting to elimiante the Nobodies, but is overpowered. After escaping, she helps Sora escape as well, so he can help her find a way to get rid of the Nobodies, by sending him and his friends into the Realm of Darkness. There, they find the two clues needed to unlock the identity of Roxas, as well as the way to unlock the second set of adventures in each World.
On the third and final main visit to Hollow Bastion, the Master Control Program has taken over Cid and Ansem the Wise's computers, causing the claymores in Hollow Bastion to malfunction and attack the residents. Sora, Donald, and Goofy go into Space Paranoids to contact Tron while Cid works on a program to delete the MCP. When downloaded into the Space Paranoids, the party is able to retake control of Hollow Bastion's computers and restore order. In addition, Tron finds information on Ansem's data of Hollow Bastion's existence before the Heartless came, then reveals it to all residents, reminding everyone its true name and nature: the Radiant Garden.
Alternatively, Sora and co. find and fight Sephiroth at Villain's Vale after Radiant Garden's chaotic situation is solved. If he is proven victorious, Sephiroth tells him to find Cloud so that they may finish everything once and for all. Cloud and Sephiroth emit in a great battle until Tifa arrives and renews his light, giving him the strength to fight Sephiroth. Cloud and Sephiroth disappear to once again finish their battle. Tifa gives Sora the Fenrir Keychain as token for her gratitude for helping her and Cloud.
Kingdom Hearts Coded
- Main article: Hollow Bastion
Following the demise of Organization XIII, Lea wakes up in the computer room and notices that he has reverted to his original human form. He ventures into Ansem's study, where he finds Dilan, Even, Aeleus, and a now-adult Ienzo. They also take note that Braig and Isa are mysteriously missing, prompting Lea to decide to go and search for them.
After Sora and Riku's Mark of Mastery exam, Lea returns to Radiant Garden.
- As with Destiny Islands and Twilight Town, the only characters native to this world are either Kingdom Hearts-original characters or Final Fantasy characters.
- Eight members of Organization XIII come from this world. Additionally, Sora lost his heart here as well, creating his and Kairi's Nobodies.
- Although they were originally set to appear in Kingdom Hearts Birth by Sleep, Leon, Yuffie, Aerith, Cloud, Tifa, and Cid were removed from the game because, according to Nomura, there were too many plot lines already, and it would have gotten confusing.
- Pre-release screenshots and trailers for Kingdom Hearts Birth by Sleep showed Terra conversing with and carrying Ven in The Great Maw from Kingdom Hearts II. However, this area wasn't included in the game at all, and the scene was moved to the Land of Departure.