Thor (トール Tooru?) is one of the three powerful countries that governed over the world of Aselia during the period between Tales of Symphonia and Tales of Phantasia. It sinks into the bottom of sea by the collision of the comet Samier, and its last remaining city becomes known the name of the Ancient City of Thor (超古代都市トール Choukodai Toushi Tooru?), though its original name is Thor City (トールシティ Toorushiti?).
Thor is found to the extreme northwest on its own island. Though it was sunk to the bottom of the ocean floor, its structures are mostly intact due to its powerful force field, save for the overgrowth from its abandoned nature. Thor's city is from a highly-advanced civilization specializing in technology and dependent on electricity and oil for power, evident by texts found in the libraries of Euclid and Alvanista.
Its buildings are made of metal and feature comforts far greater than those of the rest of Aselia. The northeast building still contains a working holographic television that continues to run programs from the city's last days, while the rear shows a glimpse of what Thor was like, full of high-rises and skyscrapers. A Chefbot waits in the the southeast building with the Fruit Cocktail recipe. Its locks are protected and can only be opened using card keys. Thor has a Common Room, which is overrun with monsters and rogue automatons. The door locks behind anyone who enters, but a key can be found in one of numerous treasure chests in the room. The key can unlock the storage room, return doorway, or path to the Mother Computer Room, where the AI Cust (オズ Ozu?, "Oz") oversees the city's functions.
In its prime, Thor was one of the world's superpowers, alongside the Kingdom of Fenrir and Republic of Odin. Unlike Aselia's present countries, it was not a monarchy, but a republic. It saw its last days during the tenure of President Galga. When it was announced that Samier would hit the city, people in Thor became panicked, but the Thor Research Lab was quick to pacify the populace by claiming only the comet's tail would graze the planet, and no direct hit would ensue. On December 2, war erupted between Fenrir and Odin. Thor was a neutral party and attempted to solve the crisis peacefully, but President Galga gave an interview that he was not adverse to ending the violence with a bombing run.
Eventually, the comet Samier struck Aselia, and Thor sank into the sea. Though Thor's force field protected the city, food supplies depleted, and its generation ceased to exist. Thor, at some time in the past, captured Aska, the Spirit of Light, in order to study it. Thor performed some investigations on the Spirit; however, researches could not make many progress, and Aska was ultimately stored in a special container. Hundreds of years later, in Tales of Phantasia, Cress Albane and his companions, with the aid of the Spirit Undine, travel to the sea's depths to use Thor's time machine to return to their time, unintentionally causing Thor to rise from the sea; because of this, Cress and company are known as the first to discover the ancient city.
Alvanista's exploration team makes an expedition to Thor, where they are able to confirm that Thor belonged to an ancient civilization long before their written history. Thor's people lived differently compared to the present-day inhabitants of Aselia. Technology and robots were considered a part of daily life. The people also loved to listen to music with an extremely fast tempo, as described in a text in the library of Alvanista. As with the other countries, it wielded an item that became known as one of the "Three Weapons", the base of the Eternal Sword: the "Diamond Ring", found after Cress and his allies defeat the robot guardians of the Mother Computer Room.
- In Norse mythology, Thor is a hammer-wielding god associated with thunder, lightning, storms, oak trees, strength, destruction, fertility, healing, and the protection of humankind. Due to his affiliation with lightning, Thor is roughly considered to be the Norse equivalent of the Greek god Zeus and the Hindu god Indra.