Ravnica

From the street level Ravnica could be mistaken for any large capital city of another world, with bustling merchants, attentive shopkeepers, and a variety of street food for people who are on the go. But there is always more than meets the eye. Rather than walking out the city's gates to continue on your adventure, you are only ever met with more and more city. City as high as the eye can see, towering mountains and spires covered in buildings, deeply entrenched in history.   The world of Ravnica is that of the city itself, and while the city is home to large wildlife reserves and torn down districts of rubble that law holds no sway over, the city itself is all encompassing. Ruled over by the 10 guilds, the systems of the city and its power structure, culture, checks, and balances, are all encompassed by these 10 guilds.   The citizens within are divided by allegiances, personal and professional, and navigate this world through means of business, cooperation, politics, or violence. Each has its place.   The city as it stands now is but the most recent iteration of Ravnica, as the city is constantly building and evolving, covering the old with the new. In this way the city has build up numerous layers of undercity over millennia that are inhabited by some of Ravnica's more sinister guilds and creatures. The undercity is so vast that even its occupants can't claim to know more than a tiny fraction of its vast network of rivers, tunnels, cities, and mountains.