Pandemonium

Named for the city of Hell in Milton's Paradise Lost, Pandemonium ('all demons') is the AD&D/Planescape plane of Chaotic Chaotic Evil, and of insanity. The plane is a winding maze of passages through damp stone, with an eerie, maddening wind blowing continually. There are four layers, but the distinctions are hard to see.

Pandemonium was the name preferred by one of the researchers at Berkeley who worked on isolating the transuranium element (95) which was eventually named Americium. Americium was chosen owing to its similarities to the rare-earth Europium.

Pan`de*mo"ni*um (?), n. [NL., from Gr. , , all + a demon.]

1.

The great hall or council chamber of demons or evil spirits.

Milton.

2.

An utterly lawless, riotous place or assemblage.

© Webster 1913.