Rivers of slow-moving, viscous sludge waft toxic fumes over stone bridges and inhabitants walk through wearing gas masks and treated leather to protect themselves. Lush forests on the edges of town have grown through the long-abandoned housing and broken apart the cobblestone roadways with their gnarled roots. Tall buildings pierce above the fog at various points allowing the rich a sense of separation from what they consider filth below.
It just so happens that the major city known as Ravnica became the name of the plane as it became consumed by metropolis. What does the world of Ravnia look like? The plane of Ravnica is comprised entirely of a cityscape.