Hells court is built deep in a gloomy vale, High walled with strong damnation, moated round With flaming brimstone. Dr. Joseph Beaumont.Hell, Verse 1.
There is in hell a place stone-built throughout, Called Malebolgë, of an iron hue, Like to the wall that circles it about. Dante.Inferno. Canto XVIII. Line 1. (Wrights Transl.)