Pandæmonium (Paradise Lost)
"Pandæmonium" (in some versions of English "Pandemonium") stems from the Greek "παν", meaning "all" or "every", and "δαιμόνιον", a diminutive form meaning "little spirit", "little angel", or, as Christians interpreted it, "little daemon", and later, "demon". It thus roughly translates as "All Demons", but can also be interpreted as Παν-δαιμον-ειον, Pandemoneios or "all-demon-place".
John Milton invented the name for the capital of Hell, "the High Capital, of Satan and his Peers", built by the fallen angels at the suggestion of Mammon at the end of Book I of Paradise Lost (1667). It was designed by the architect Mulciber, who had been the designer of palaces in Heaven before his fall. (In Roman times, Mulciber was another name for the Roman god Vulcan.) Book II begins with the debate among the "Stygian Council" in the council-chamber of Pandæmonium. The demons built it in about an hour, but it far surpassed all human palaces or dwellings; it was probably quite small, however, as its spacious hall is described as being very crowded with the thronging swarm of demons, who were taller than any human man, until at a signal they were shrunk from their titanic size to less than "smallest dwarfs". It was also reputed to be made of solid gold.