The basic unit of the polycatenane can differ from the relatively simple organic macrocycle. When organic and inorganic building blocks come together can form a coordination cages (or macromolecular cages) that can interlock one another to form a polycatenane structure. The mechanism is still unexplored but generally the subunits self-assemble into a 0D cage and, in a concerted process, they interlock together into a linear or more intricate catenane structure. Sometimes the catenated cages structure is more stable with respect to the monomeric cage state, and it can be formed passing through a favored reaction intermediate. The synthesis can follow a statistical or a directed routes, forming more or less product, but there are some cases when post-synthetic modifications can increase the product yields. Catenated cages can be applied in a wide range of application due to the high presence of voids.