El Dorado

Golden City El Dorado (黄金郷エル・ドラード) is the country ruled by Demon Lord Leon Cromwell, located on another continent larger than Australia on Earth.

Overview
It is wide and has towns divided into districts. Forest, Field, Lake, River, and Mountain districts. Every sector is protected via a magic circle. An artificially created land of nature and tranquility–a magic city.

There's a gigantic active volcano in the center of the continent, emitting smokes and flames throughout the year. The beautiful capital and Leon's palace was built nearby, but volcanic ash and smoke never entering into the city thanks to barriers and magically produced winds.

One of the hell gates also happened to be situated near the capital, which was where Carrera and her subordinates manifested themselves to harass the city before she pledged her loyalty to Rimuru.

Economy
El Dorado is a country that makes full use of its natural reserves of precious metals drawn out from the earth by the volcano at its center. Much of the nations people are miners, with them pulling enough metals like Gold, Silver, and Platinum to make the capital’s buildings shine. Some of its gold is sometimes discreetly traded with Sarion via private Dragon Airships, being traded for market goods that aren’t produced locally.

Trivia

 * Leon seems to have named his country after the legendary city of gold. Which is Spanish for "The Golden One".
 * Leon has a personal squad of knights who are in color coded armor, akin to Super Sentai/Power Rangers.