Kokunabaya

"Describe a ruined structure that nature has reclaimed. What was its original purpose?"
Kokunabaya (originally pronounced "Chokunbaya") was an ancient city located in Koliv beside the Opriva (Stone River). It was considered one of if not the most propserous city of its time.
Hundran explorer and chronicler, Jonristastun, visited the city in the year 823 and called it (in Native Hundran) "Themnrt," meaning "Golden City." He described many beautiful monuments to the Goddess Akinara, who had blessed Kokunbaya, which were covered with magnificent gardens that "flowed like green waters toward the earth below." According to his descriptions, the residential buildings were made of magical wood which could never burn, decorated with gold, silver and bones and typically had the names of the owners of the home and their ancestors carved in the doorframe.
The residents of the city had no king but instead bowed to Akinara, as did all of Koliv. However after the nation's betrayal and spiting of their Goddess in 986, the nation was cursed. The gold, which had been gifted to the people by Akinara, turned to mud and the forests turned to desert. The people's skin turned dark, to forever mark them as those who invoked Akinara's rage.
Kokunabaya one amongst many settlements in the region that were abandoned in time after this event. However, it is a unique case. While most abandoned settlements were left mainly due to a lack of water and related resources, kokunabaya had access to water via the krova. Akinara's fury was targeted towards kokunabaya especially amidst all settlements in Koliv, to the extent that they were perpetually under threat of wild animal attacks, natural disasters and plague.
After its abandonment, kokunabaya was reclaimed by its new environment. It is now an eerie ghost town, etched with the names of long-dead men and women, and stands as an eternal reminder of the great might and fury of Akinara.