For The Fashion Of Minas Tirith Was Such That It Was Built On Seven Levels,
Each Delved Into A Hill, And About Each Was Set A Wall, And In Each Wall
Was A Gate.
For the fashion of Minas Tirith was such that it was built on seven levels,
each delved into a hill, and about each was set a wall, and in each wall
was a gate.
-- J.R.R. Tolkien, "The Return of the King"
[Quoted in "VMS Internals and Data Structures", V4.4, when
referring to system overview.]