Abstract-In the paper, we present the topological counterpart supporting rich formal apparatus describing properties of rough sets within one of the largest repositories of computerized mathematical knowledge, the Mizar Mathematical Library. The paper develops third and final (after lattice theory and the theory of general binary relations) planned path designed to be linked (via mechanisms of theory merging) with the theory of structures described by Pawlak in the early seventies of the previous century. We propose the revision of the existing topological apparatus offered by Mizar, and give the outline of the formalization of uniform spaces, important objects allowing for further representation of approximation spaces.