Central World

The Foundation World (基軸世界) is the universe in which the That Time I Got Reincarnated as a Slime series primarily takes place.

Background
The original universe created by Star-King Dragon Veldanava. It serves as the basis for all other "worlds", and its location at the "center" makes it easy for people and objects from other universes to find themselves there (especially the 'Demon Realm' and 'Spirit Realm' which directly "border" it).

Magic Continent
The Magic Continent (魔大陸 Ma tairiku) is the central continent where most of the series events take place. On the far west, there are the "Barren Lands", a great expanse of inhospitable sandy desert contamined with magicule radiations and the territory of Demon Lord Dagruel, on its border lies the Holy Empire Ruberios, a rich land and the territory of Demon Lord Luminous Valentine as well as the home of the Western Holy Church.

In the center of the continent lies a great collection of countries collectively referred to as the 'Western Nations', as well as the Jura Forest which contains the Jura Tempest Federation and is the abode of Storm Dragon Veldora. Both are considered the territory of Demon Lord Rimuru, although he's only publicly the ruler of the Tempest Federation. There's also the 'Canaat Mountain Range' to the north, a great expanse of mountains ruled on the surface by the Dragon Lord(s) who reside in the 'Dragon Roost' at the peak of the tallest mountain, and ruled underground by the Armed Nation of Dwargon. And at the southern border of Jura Forest is the Sorcerer's Dynasty Sarion, a collection of 13 elven states that swear allegiance to their divine emperor Elmesia El-Ru Sarion, but otherwise act independently to each other. Its "capital" is the state of El-Ru where the emperor and his family reside.

In the eastern border of the Jura Forest lies a collection of demi-human and majin populated states collectively the territory of Demon Lord Milim Nava. Its 'Capital' is the unnamed city currently under construction at the site of the former capital of the Beast Kingdom Eurazania. And finally to the far east lies the Nasca Namrium Ulmeria United Eastern Empire or more simply 'Eastern Empire', an expansionist empire made up of over 100 cities with a population of over eight-hundred million people. In the empire, people of all races are accepted without prejudice as long as they submit themselves to the emperor and anybody can obtain political power by joining the military. It is a land of "might makes right", ruled by its eternal emperor Rudra Nam Ul Nasca. Its capital is called 'Nasca' and is located next to a great holy mountain said to house the empire's guardian deity, Scorch Dragon Velgrynd.

Ice Continent
The Ice Continent (氷土の大陸 Kōri tsuchi no tairiku) is the northern continent as well as the domain of the first Demon Lord, Guy Crimson. Its surface is constantly under a thick layer of permafrost and harsh weather due to the Frost Dragon Velzard's Aura, making it inhospitable to all but the strongest of living beings. The only known "settlement" is the Palace of White Ice, where Guy and Velzard, as well as a massive army of demons under the leadership of Rain and Misery, call home.

El Dorado
El Dorado (黄金郷 エル・ドラード Ōgonkyō Eru Dorado) is the southwest continent singlehandedly ruled by Demon Lord Leon Cromwell. It has a large and active supermassive volcano at its center that constantly spews out ash and draws out large mineral deposits from deep under the surface, including gold, the source of El Dorado's income. It was also home to a "Hell Gate", which was managed by the Primordial Yellow.

Ocean
Not much is known about the ocean or what resides in it besides the Spear Toro and 'awakened demon lord level' monsters.

Information to be added.

Barren lands
Region furthest west on the 'Magic Continent'

Information to be added.

Beast Kingdom Yuurazania
Information to be added.

Canaat Mountains
These are a set of mountains which are on the border between the Warrior Nation Dwargon and the Great Jura Forest.

Information to be added.

Capital of the Forgotten Dragon
Information to be added.

Eastern Empire
Information to be added.

Golden City of El Dorado
A city which resides besides a Volcano on the Continent of El Dorado.

Information to be added.

Great Jura Forest
Main Location of the series.

There are multiple locations of interest in the Great Jura forest and these include;

Lake Sis (Shisu Mizūmi シス湖) - Also known as Lake Shisu, this place is home to the Sissie along with the Merfolk. Also home to 'Amphibious Monsters' which had drove out the Merfolk which caused them to seek refuge in Tempest in Volume 3

Cave of Imprisonment - Information to be added.

Kusha Mountains - Information to be added.

Information to be added.

Harpy Country Fulbrosia
Information to be added.

Holy Ruberian Empire
Information to be added.

Kingdom of Brumund
Information to be added.

Kingdom of Farmas
Information to be added.

Kingdom of Ingrassia
Information to be added.

Kingdom of Siltrozzo
Information to be added.

Land of Puppets Jistarv
Information to be added.

Republic of Ulgreisia
Information to be added.

The Sorcerous Sarion Dynasty
Information to be added.

Various Western States
Information to be added.

Vast Plains
An area which is a large open plain which is in both the Great Jura Forest and the Eastern Empire

Information to be added.

Warrior Nation Dwargon
Dragon's Peak sits atop the large mountain which covers about 90% of this nation.

Information to be added.