a city roughly circular, built as a series of seven walled terraces of ascending height on the lower slopes of a mountain. a rocky outcropping from the mountain, 7 0 0 feet high and resembling the prow of a ship, divided the city in half ; road tunnels had been built through it on each level. the white tower, 3 0 0 feet high, was built on the highest point of this rocky outcropping, close to the sheer drop down to the great gate of the city. 