Est Tayiar was once a beautiful, porspering and great elven city, capital of non-human realm ruled by king Maeglor from his majestic palace on Pontar Delta (very near to where later are human-Redanian Oxenfurt and Free City of Novigrad). Later (likely) cancer or plague start to spread in city so he command earth (with his sage powers) to swallow town.
Long before men first peopled these lands, a beautiful, prospering elven city stood here, centered around the palace of King Maeglor. One day, however, the city's inhabitants began mysteriously dying off in large numbers. According to legend, King Maeglor sensed he, too, would soon perish and cast a powerful spell that caused the earth to swallow the city whole so that no outsider could ever desecrate it. Centuries later, scholars from the Oxenfurt Academy began painstaking excavations of King Maeglor's palace in a search for the causes of the catastrophe . Yet work came to a sudden halt when when three subsequent expeditions ventured into the ruins' depth - and were never heard from again...
|— In-game description|