Ruins Floating in Autumn Leaves: The Ruins Zone is a wooded area of the unnamed island Popora inhabits that is full of derelict structures. It is the third area the Straw Hat Pirates explore in One Piece: Unlimited Adventure.
The Ruins Zone is a temperate, cooler region of the game's unnamed island with thin forests full of trees that are always dropping leaves as if it were autumn. The ground in this area is often covered in multicolored leaves or short, brown grass. A stream can be found at the zone's entrance, and ponds are scattered throughout.
The Ruins Zone is home to many ancient structures, including archways, buildings, pillars, and sunken altars made of brown stone brick. They have fallen to ruin over the last thousand years of the island's history, and the remaining standing structures show signs of age like dirt and cracks. Ancient drawings were sketched onto the walls of one altar, depicting the creation of the Evil Guardian and his Majin Soldiers.
At the beginning of the game, the following enemies appear:
- Normal Marine
- Rifle Marine
- Bazooka Marine
- Marine Leader
- Saber Pirate
- Bomb Pirate
- Knuckle Pirate
After Chapter 4, the following enemies also appear:
One Piece: Unlimited Adventure
The Straw Hat Pirates entered the Ruins Zone from the Plain Zone and walked along its creek. Popora stood above them on a bridge and jumped down to attack. As he swung his hammer, Zoro blocked him with his Wado Ichimonji, and the orb showed them all memories Popora and Sealed and Zoro's promise to Kuina. Zoro deflected him and knocked the small creature back before the crew continued into the zone. There, they found the Thousand Sunny sitting on top of a hill. Usopp tried to get the crew to board and flee the island, but Nami was too focused on finding the island's treasure.
The crew came upon a sunken area full of water, and Luffy activated the orb. A huge ball of fire appeared in the air and caused all of the water to evaporate, revealing a platform and the next seal. Nami approached it, and Popora charged her. He missed, and Sanji jumped between them. As Franky lamented over Popora's pursuits, the orb showed the group memories of Popora fighting pirates who invaded the island, Franky trying to stop the Puffing Tom, and Spandam exclaiming that those who opposed justice will be completely destroyed. The seal produced an apparition of the CP9 commander, along with a group of Marines and agents. The crew defeated them, and the orb absorbed the seal's energy. Popora ran off again before Franky could talk to him.
As Luffy and his friends went deeper into the Ruins Zone, they found another altar surrounding by swirling flames. Luffy activated the orb, and springs of water burst forth from the altar's walls, quelling the blaze. Once inside, Robin noticed ancient markings and sketches on the ruins' walls. She deciphered them to reveal that breaking all of the seals would cause the orb to give shape to the desires of those who break them, but it would also release a great evil upon the world. The crew learned that the seals were put in place to keep the monster trapped away. Popora appeared and dove at Usopp, knocking him over. The orb showed them memories of the island's civilization being burnt to the ground by the Evil Guardian and Enel wreaking havoc on Skypiea. The seal produced an apparition of the tyrant, and the crew fought and defeated him. The orb absorbed the seal's energy, causing the third of six seals on the Abyss Zone's entrance to shatter. Robin and the crew realized that Popora was protecting the Evil Guardian from being released, and Luffy asked Popora to how long he had been doing so. Robin estimated about 1,000 years according to the ancient writings.
Suddenly, a monster appeared out of a black vortex that formed in the ground. The Sword Solder charged at Usopp, and Popora jumped in the way to attack it. He swung at the monster again, but the Sword Soldier countered with a sword slash and grabbed Popora by his head, pulling him back into the vortex below them. Nami decided that she wanted to leave, but Franky and Luffy wanted to help Popora. The crew left the Ruins Zone to return to their camp and save Popora.
Oil Stain Frogs can be caught in the stream after the Ruins Zone's entrance. Honeybees, Swallowtail Butterflies, Hidden Black-winged Swallowtails, and Doze Evil Eye Butterflies can be found on the zone's flowers, while Hercules Beetles and Fire Hercules can be found on the zone's trees. Weir Storm Mice reside within and around the area's ruins.
- The Ruins Zone was one of two of Unlimited Adventure's areas shown off in their early build stages, along with the Plain Zone. In its early stages, it lacked its autumn season theme, and the ruins themselves were turquoise instead of brown. This early build was the setting for the game's E3 2006 demo.