The Nameless City of the story’s title is an ancient ruin located somewhere in the deserts of the Arabian Peninsula, and is older than any human civilization. In ancient times, the Nameless City was built and inhabited by an unnamed race of reptiles with a body shaped like a cross between a crocodile and a seal with a strange head common to neither, involving a protruding forehead, horns, lack of a nose, and an alligator-like jaw. These beings moved by crawling; thus, the architecture of the city has very low ceilings and some places are too low for a human being to stand upright. Their city was originally coastal, but, when the seas receded, it was left in the depths of a desert. This resulted in the decline and eventual ruin of the city.[…]
Another identified source is the 9th Edition of the Encyclopædia Britannica, whose description of “Irem, the City of Pillars” he copied into his commonplace book: “which yet, after the annihilation of its tenants, remains entire, so Arabs say, invisible to ordinary eyes, but occasionally, and at rare intervals, revealed to some heaven-favoured traveller.”[3]
Source: The Nameless City – Wikipedia
Tim B.
http://www.timboucher.ca/2019/09/iram-of-the-pillars-islamic-mythology/