Erbisterra

Erbisterra was a mythological city on Mergis which, according to legend, was the only habitable location on the planet other than Mergis City. It was said to be a beautiful city made almost out of rare crystals and metals, and it was thought to be a bastion of extraordinary technology. Descriptions of the city varied over time as social trends changed and technology advanced, however it was always thought of as a sort of paradise. The legend of Erbisterra was especially popular prior to the introduction of the Mergis Worker's Act, when the miners were working under incredibly dangerous and unsanitary conditions, however it persisted after this.

Origin
The origin of the legend was with one miner, Alvan Wyzze, after he safely appeared in Mergis City after going missing on a surface expedition a few months prior. The man claimed to have been rescued by a group of mysterious aliens who took him to Erbisterra. Consequent occasional recounts of similar experiences by other miners strengthened the legend, though several expeditions which sought to locate the city failed.