Today I learned there are people who get paid to make Minecraft worlds for private clients, entire teams of builders and designers who work to spec. One such team is Varuna, and they're responsible for the city seen here.
Though it looks a bit like the Imperial City from Oblivion to me, it's actually the the Labyrinth City of Orario from the anime/manga/light novel series Is It Wrong to Try to Pick Up Girls in a Dungeon? Every building has its own interior, and the central tower-dungeon hits Minecraft's upper limit for verticality.
It apparently took over two months' worth of roughly 12-hour days for the Varuna team to make, so whatever the client paid for it I imagine it must have been steep. Of course, being a private creation means we can't download it and have a look for ourselves so we'll have to content ourselves with the screenshots from their website.