Minas Tirith - The White City.

"For the fashion of Minas Tirith was such that it was built on seven levels, each delved in the hill, and upon each was set a wall, and in each wall was a gate.  But the gates were not set in a line: the Great Gate in the City Wall was at the east point of the circuit, but the next faced half south, and the third half north, and so to and fro upwards; so that the paved way that climbed towards the Citadel turned first this way and then that across the hill.  And each time that it passed the line of the Great Gate it went through an arched tunnel, piercing a vast pier of rock whose huge out-thrust bulk divided in two all the circles of the City save the first.  For partly in the primeval shaping of the hill, partly by the mighty craft and labour of old, there stood up from the rear of the wide court behind the Gate a towering bastion of stone, its edge sharp as a ship-keel facing east.  Up it rose, even to the level of the topmost circle, and was crowned by a battlement; so that those in the Citadel might, like mariners in a mountainous ship, look from its peak sheer down upon the Gate seven hundred feet below." ~The Return of the King, Book V, chap. 1 (Minas Tirith)