Sylvarant is the starting world in Tales of Symphonia. It is part of the cross-dimensional world Aselia, mirrored by another world, Tethe'alla. As per tradition, there exists a Chosen who is sent to regenerate the world by making a pilgrimage to the elemental seals and, finally, the Tower of Salvation, an enormous tower that reaches to the skies when it is time for the Chosen to go on the Journey of Regeneration. Sylvarant's moon is named "Tethe'alla", and "Sylvarant" is the name of Tethe'alla's moon. In Tales of Phantasia, Aselia has two moons—both of which are named after the dimensions that were fused to create it.
Sylvarant is mostly a verdant planet abundant in trees and mountains. Its geography is comprised of four continents, albeit relatively unnamed. Its largest continent houses the Asgard region and its subsidiaries, which include Luin, Hima, the Tower of Mana, and the subcontinent of Balacruf. The Tower of Salvation also nests here when the Chosen's Journey of World Regeneration begins. The continent has two lakes: Lake Umacy and Lake Sinoa, which rests beneath Luin and splits part of the continent with a river that connects the lake to the ocean. While Hima is situated in the western part of the continent's large and only mountain chain, Asgard resides on the eastern part. The subcontinent of Balacruf houses the Balacruf Mausoleum, a relic of the ancient Balacruf Civilization, and the Asgard Human Ranch is stationed on the northeastern portion of the continent, terrorizing nearby settlements—particularly Luin. Hakonesia Peak connects the large continent with the smaller continent attributed to Palmacosta.
The Palmacosta continent is relatively empty, apart from its main city and the Palmacosta Human Ranch that lurks just behind the nearby mountains. Partially split by a small river, the continent is defined by a long trail that spills down from Hakonesia Peak. On the eastern coast lies Thoda Dock, which offers transportation to the Thoda Geyser island. Sylvarant's southwest continent is home to the forested village of Iselia, as well as the Iselia Human Ranch hidden within Iselia Forest. The lower portion of the continent is marked by Triet Desert and its accompanying town and ruins, as well as the Renegades' Sylvarant Base. While the desert opens to its northern path to Iselia, mountains close the eastern side, and Ossa Trail cuts through the mountains to the small fishing port of Izoold. The continent's northeastern tip barely connects it with the Asgardian continent. In Sylvarant's northwestern hemisphere, a lone continent—the planet's smallest—houses only the small Katz Village.
- Iselia - Known as the Village of Oracles, Iselia is the hometown of Lloyd Irving, Colette Brunel, Genis Sage, and Raine Sage, as well as the place where Colette receives her Oracle. Despite being the hometown of the four heroes, Colette is the only one born in the village. Lloyd lives on the outskirts of the village with the dwarf Dirk. Genis and Raine came to the village years ago, claiming to be elves in order to live there, as half-elves are commonly discriminated against. Raine serves as the teacher of the local schoolhouse, and Lloyd, Colette, and Genis all attend school there. When the Chosen, Colette, was born, Iselia made a treaty with the Iselia Human Ranch that stated, as long as the two locations do not interfere with each other, the half-elven Desians of the ranch will leave the village alone. This was for the purpose of protecting Colette, as it is believed that the Desians oppose the Chosen. The village is later destroyed under the Desian Grand Cardinal Forcystus's due to Lloyd and Genis breaking the treaty based on the belief that the Desians had broken it first. Lloyd and Genis are subsequently banned from the village for their actions.
- Triet - Known as the Desert Oasis, also called the Flower of the Desert, Triet is a desert town located in the large desert that shares its name. Lloyd and Genis visit Triet in pursuit of Colette and her companions, who left on the Journey of Regeneration without Lloyd and Genis. Upon discovering that the Chosen's group has gone to the nearby Triet Ruins, Lloyd and Genis being making their way there, only to be captured by who they believe to be Desians in the process and taken to the Sylvarant Base, which is actually a Renegade base. After the events at the base, the group returns to Triet to prepare for the Seal of Fire at the Triet Ruins. In Tales of Symphonia: Dawn of the New World, the town is blanketed in snow due to the Centurion Ignis being in a core state.
- Izoold - Known as the Small Fishing Port, Izoold is a port town for fishermen that has access to sea travel. The group first reaches Izoold after passing through the Ossa Trail and eventually board a ship en route to Palmacosta. Izoold is a small seaside town that thrives on fishing, and it has the second largest yearly catch in all of Sylvarant. The different seafood products made at the port town are known around the world—especially Izoold's most famous souvenirs: red blowfish cakes and "Seafood Gels". Izoold sits on the coast and effectively serves as a fishing port with docks built near the water. The buildings are primarily constructed from wood, with stones on rooftops—a safety precaution commonly utilized by people who live near water to prevent destruction in case of storms or other forms of violent weather.
- Palmacosta - Known as the Port City, Palmacosta is the largest city in Sylvarant, as well as the only city openly rebelling against the Desians. Although it is not officially recognized as such, Palmacosta is often regarded as Sylvarant's capital. The city and its surrounding rural areas are governed by the Governor-General. It is also home to the highly elite school, the Palmacosta Academy. Palmacosta is largely built on small islands off the southwestern coast of the Sylvarant's eastern continent. The city is filled with many canals and bridges. The only university and cathedral in Sylvarant are located here, as well as the largest steam ship. The Desian Grand Cardinal Magnius frequently terrorizes this city.
- Asgard - Known as the City of Ruins, Asgard is an ancient city known worldwide for its historical ruins. The city is popular among tourists, and it is believed to be the capital of the ancient Balacruf Civilization. One of the city's central features is its stone dais, where Cleo III once held a ritual to offer a sacrifice to the Summon Spirit of Wind in order to quell a storm that had raged for a week, and the altar was made for the Spirit. The curve of the stone is said to express the Spirit's flight through the sky, and that it is infused with a large volume of mana—although currently, due to the world's mana shortage, the mana infused in the stone is fading. When the mana in the stone evaporates, it emits a unique aroma that is commonly known as the "Filament Effect".
- Luin - Known at different times by the titles City of Hope, City of Devastation, City of Rebirth, and City of Water, Luin is a city in the center of the Balacruf region that resides near the Asgard Human Ranch. Built on Lake Sinoa, the city is known for hiding refugees and people who have escape from the ranch. When the Desian Grand Cardinal Kvar discovers that prisoners who have escaped from his ranch are hiding in Luin, he invades the city and takes every survivor as prisoners. Although Sheena Fujibayashi attempts to help the citizens, she fails, later assisting the group in a rescue mission at the ranch. Managing to rescue its citizens from the ranch by killing Kvar, the group later assists in rebuilding the city to its former glory and greater. In Dawn of the New World, the city becomes victim to an onslaught known as the Blood Purge.
- Hima - Known as the Village of Adventures, Hima is the last town visited by the Chosen's group before entering the Tower of Salvation for the first time. A quaint cliff-side village, Hima offers few amenities, but it does house convenient dragon transportation that the group uses in reaching the Tower of Salvation.
- Katz' Village - A town populated entirely by Katz, a species similar to humans in cat costumes. The village is located on an island in the northern hemisphere of Sylvarant, accessible only by air.
- Martel Temple - Also sometimes referred to as Iselia Chapel, Martel Temple is where the Chosen receives his or her Oracle. It later becomes the home for the Summon Spirit of Heart, Verius.
- Iselia Forest - An area of woodland near Iselia that houses the Iselia Human Ranch and leads to Dirk's House. The powerful Sword Dancer can be fought for the final time here, if all necessary circumstances are met.
- Triet Ruins - Ancient ruins buried within the Triet Desert. The ruins lie near the desert town Triet and house the Seal of Fire, where the Summon Spirit Efreet is fought. In Dawn of the New World, the ruins are covered in snow in a similar fashion to Triet.
- Sylvarant Base - Located in the Triet Desert, the base serves as the Renegades' Sylvarant stronghold.
- Ossa Trail - A mountain path the group passes in order to reach Izoold upon leaving the Triet Desert. It is where Sheena is first encountered and fought, as well as where the Sword Dancer can be fought for the first time.
- Thoda Geyser - A tourist-friendly, hot spring island accessible through the Thoda Dock that houses the Seal of Water, where the Summon Spirit Undine is fought.
- Balacruf Mausoleum - Historical ruins located near Asgard that house the Seal of Wind, where the Summon Spirit Sylph is fought.
- Tower of Mana - The fourth and final seal of Sylvarant—the Seal of Light, where the Summon Spirits Luna and Aska are fought after the group's expedition to Tethe'alla.
- Tower of Salvation - A tower that appears initially in Sylvarant after Colette receives her Oracle at the Martel Temple, initiating the Journey of World Regeneration and serving as a beacon of hope for the people.
- Iselia Human Ranch - Located in the Iselia region, led by Forcystus.
- Palmacosta Human Ranch - Located in the Palmacosta region, led by Magnius.
- Asgard Human Ranch - Located in the Asgard region, led by Kvar.
- Remote Island Human Ranch - Located on a remote island, led by Rodyle.
- Dirk's House - Home to Lloyd and his dwarven foster-father, Dirk.
- House of Salvation - A hermitage chain sprawled throughout Sylvarant where weary travelers can rest and practice their faith in the goddess Martel during long pilgrimages.
- Thoda Dock - A small port area that provides washtubs that sail to the nearby Thoda Geyser.
- Hakonesia Peak - A small mountain trail that connects the Palmacosta region with the Asgard region. The collector Koton lives here.
- Lake Umacy - A lake hidden within a forest on the Asgardian continent. It is where the group obtains the legendary "Unicorn Horn" that has the power to heal.
- Nova's Caravan - A roaming caravan comprised of a family seeking the legendary Spirit Aska.
- Linkite Tree - An ancient, withered tree that produces a special fruit known as "Linkite Fruit". The tree is accessible only by air.
Sylvarant was once a country part of the world known as Aselia. Around 5,000 years prior to the events of Tales of Symphonia, a conflict known as the Kharlan War ignited between Sylvarant and another country, Tethe'alla, due to the advent of magitechnology. The war lasted for at least 1,000 years, when finally, a young boy—who would later become known as Mithos the Hero—successfully forged pacts with the world's Summon Spirits and ended the war with his three allies. The war, however, caused irreversible damage to the planet's World Tree—the source of the planet's mana—so Mithos used the Eternal Sword to manipulate space-time and split the planet of Aselia into the separate planets of Sylvarant and Tethe'alla. Due to the mass depletion of mana, the two worlds became forced to vie for mana in a seesaw-oriented system of mana links. Mithos constructed a system in which the hourglass planets house an even number of Summon Spirits to correlate yet oppose the other planet's Spirits in an elemental fashion. Through this system, neither planet was able to advance too greatly in technology before succumbing to the opposing planet's accumulation of mana. This aids in deterring the reinvention of magitechnology and a return of war.
In an effort to manage the balance of mana between the two worlds, a Chosen of the lesser planet embarks on the Journey of World Regeneration to unlock the seals at a series of elemental temples. The unlocking of these seals leads to the reversal of the mana links, which in turn, redistributes the flow of mana into the declining world from the more prosperous world—thereby leading to its decline while the lesser world's civilization is given the opportunity to progress forward. The process is repeated when the flourishing planet grows too advanced technologically, and the opposing world's Chosen ventures on the regeneration journey to reverse the mana links once again. Around 800 years prior to the events of Tales of Symphonia, the Chosen Spiritua successfully managed to reverse the mana flow in favor of Sylvarant, leading to the prosperity of the Sylvarant Dynasty. This point in history is widely considered to be Sylvarant's glory period. During the events of Tales of Symphonia, Sylvarant is in the declining state of balance of the mana flow, with its mana being fed to Tethe'alla, although evidence shows that Sylvarant has been in decline for a fairly long time due to the multiple failed Chosen following Spiritua's success. Similarly, this is the cause for Tethe'alla's significantly more advanced technology, having had centuries of development and progress due to the higher concentrations of mana.
- In Norse mythology, Asgard is one of the Nine Worlds and home of the Aesir, whose leader, Odin, rules the planet from Valhalla.
- Throughout the Balacruf Mausoleum, there are several scripts on the walls that hint at how to successfully complete the trials. They also provide a brief history of the Balacruf Civilization:
- The world is a giant. Its ruby left hand is the throne of gods. Its emerald right hand is the power of gods. Its pearl white left leg is the calm earth. Its topaz right leg is the rich earth. And its lapis lazuli body is the blue wind princess.
- The Balacruf are people of the wind. They are born with the wind, live with the Summon Spirit, and become as wind when they die.
- The great King of Balacruf, Cleo III, died and was reborn as the king of the wind. The king travels the heavens with the Summon Spirit in past, present, and future.
- The holy seal that extols the king flows from the throne of the gods to the rich earth, travels from the power of gods to the calm earth, and when the blue wind princess is born in the center of the world, the holy seal shall also be complete.
- That which the blue wind princess protects heads from the throne and across the rich earth, stands upon the calm earth, and gazes up at the power of gods.
- That which is offered to the throne of gods from the power of gods, makes the rich earth as the calm earth, and arrives at the blue wind princess, will be as if traveling the giant's body in the manner of a clock's hand.
- The Summon Spirit and the wind that serves it are to be found beyond the carving of the holy seal.