text: Of course it was built , but it was built vertically within the city walls, meaning that new buildings were constructed atop existing ones like so: The effect is the sort of architecture one only finds in dreams or representations of them, like the one in the finale of the fourth season of Buffy the Vampire Slayer , wherein Joss Whedon took advantage of contiguous three-walled film sets to depict Xander Harris moving seamlessly from the upstairs bathroom at Buffy's house: