E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Chilminar and Balbec.
Two cities built by the Genii, acting under the orders of Jan ben Jan, who governed the world long before the time of Adam. Chilminar, or the Forty Pillars, is Persepolis. These two cities were built as lurking places for the Genii to hide in.