Snow-capped Mountains Frozen in Silver: The Mountain Zone is a wintery area of the unnamed island Popora inhabits. It is the fifth area the Straw Hat Pirates explore in One Piece: Unlimited Adventure.
The Mountain Zone is a frigid, snow-covered area named after its mountainous terrain. It has icy foliage and coniferous trees that are resistant to the cold. Most of the ground in the region is covered in either snow or ice, the latter of which is thick enough to support human weight. The uncovered areas are dark and grassless. There are multiple ponds that are somehow not frozen over, and the central mountains have a winding path that ascends up to its peak. On the mountains themselves, parts that are not covered in snow reveal dark grey rock underneath.
At the beginning of the game, the following enemies appear:
- Normal Marine
- Bazooka Marine
- Marine Leader
- Saber Pirate
- Bomb Pirate
- Sword Soldier
- Knuckle Soldier
- Golem Soldier
- Red General
- Green General
- Violet General
One Piece: Unlimited Adventure
The Straw Hat Pirates entered the Mountain Zone from the Plain Zone. As soon as they arrived, Luffy and Usopp built snowmen, and an annoyed Sanji kicked them down. Approaching the area's mountains, Luffy and Usopp ran ahead in excitement. Chopper asked Popora if he had a name, and the orb showed them his memory of being created from clay and brought to life by Sealed, as well as being named. Chopper commented on the old man being Popora's master, and the orb showed another memory of the island's residents trying to convince Sealed to bring a statue of the island's deity to life. Popora cried out in pain for his fallen master, and Sanji bent down to relate to him, putting his hand on the creature's head. The orb showed a memory of Sanji leaving the Baratie and thanking Zeff for caring for him. The group stood up and continued into the zone to explore it.
Descending a path toward a deep-set part of the Mountain Zone, the crew came upon a pond, and Luffy activated the orb. It forced a series of ice platforms to shoot up from the pond and make a path toward the region's first seal. Robin asked if it was okay to break the seal, and Popora and Franky affirmed. The orb showed them memories of the island's residents stealing Sealed's orb to bring the island's deity to life, Sealed warning Popora to hide from danger, and Ace promising to meet up with Luffy after leaving Arabasta. The seal produced an apparition of Ace, who the crew fought and defeated. The orb absorbed the seal's energy, and the group continued to search for the next seal.
After climbing most of the way up the mountains, the crew came upon an area with dense ice. Luffy activated the orb, and the ice shattered, revealing a group of Majin Soldiers, including a Red, Green, and Violet General. The crew defeated them to find another seal. They opened it, and the orb showed them memories of the Evil Guardian wreaking havoc on the island after being brought to life, Sealed swearing to seal the evil monster away, and Shanks giving Luffy his straw hat. The seal produced an apparition of Shanks, who the crew defeated. The orb absorbed the seal's energy, causing the fifth seal on the Abyss Zone's entrance to break. The crew talked about Shanks before returning to camp.
- One Piece Video Games – One Piece: Unlimited Adventure, The Straw Hat Pirates and Popora journey through and break the seals of the Mountain Zone.