Decarabian's Mondstadt, commonly referred to as Old Mondstadt, was the original location of the nation of Mondstadt. It was created by the God of Storms, Decarabian, who built his capital city within a deep valley and created a large tower from which he ruled. His reign ended 2,600 years ago, when his people rebelled against him and ultimately slew him. Afterwards, the newly crowned Anemo Archon, Barbatos, moved the people of Mondstadt to Cider Lake, where the current-day City of Mondstadt was built.
During the cataclysm five hundred years ago, Dvalin took up residence in Decarabian's tower to recover from the injuries incurred during his battle against Durin. In subsequent years, after the people of Mondstadt forgot about Dvalin, the area of Old Mondstadt became known as Stormterror's Lair.
Little is known about the initial creation of Mondstadt, but Decarabian's City is described as a "dream of prosperity" which was "created entirely by his divine might." His territory spread to the Brightcrown Mountains and Windwail Highland areas to the east and south, as evidenced by the ornamentation on some of the ruins in the area. Besides Decarabian's City, notable cloisters of ruins in its ornamentation style include the ruins in Brightcrown Canyon leading into the city, and the ruins around Cecilia Garden.
When the region of Mondstadt was blanketed in snow and ice as a result of Andrius' powers, Decarabian created an impenetrable storm wall around his capital city to protect those dwelling within from the bitter cold.
Architecture and Design
The architectural style of the ruins in Decarabian's Mondstadt is quite distinct from those found in the rest of modern-day Mondstadt, making it easy to identify ruins outside of the Stormterror's Lair area that are related to it.
Tall bridges are a distinctive feature within Decarabian's City and in the surrounding area.
Notably, the ruins associated with Decarabian's style lack symbols otherwise commonly seen in Teyvat, such as the triquetra. Instead, a symbol seen on ruins of Decarabian's Mondstadt is a cercelée, a type of cross with curled-in ends. The ornamental designs seen on bridges, pillars, and walls are margents, or plant-like motifs, rather than the Celtic knots commonly seen on ruins throughout Teyvat. (In a similar vein, the Wolf of the North arena in Wolvendom is decorated with Arabesques, another type of plant-like design, rather than Celtic knots.)
The structural integrity of Decarabian's ruins are apparently quite sturdy despite their age, remaining in rather good condition in the 2,600 years since its fall. Alice destroyed several arcades inside the tower to make it easier to climb, and the tower has remained stable despite that.
Decarabian micromanaged his city, to the point of arranging who lived where. Even in the present, the residential area of the city is clearly delineated, suggesting that the city's layout was also something Decarabian determined.
Under Decarabian's rule, certain tunes and chords were banned due to their association with dissent and rebellion.
Based on the similarity between ruin structures as well as in-game documentation, the original scope of Old Mondstadt's territory encompassed the Brightcrown Mountains and Windwail Highland areas, and went as far south as the Teleport Waypoint between Liyue and Dawn Winery. It is currently unknown how far north or west it covered.
The most well-known settlement of Decarabian's Mondstadt was his capital city, located in the area now known as Stormterror's Lair. It is located within an extremely deep, possibly manmade valley; it is currently one of the deepest locations on the explorable part of the Teyvat map.