This is a highly detailed model of a world inside a plain object. The outer shape resembles a tennis racket, but the inner structure shows structural spaces with roofs and columns. The geometry is very clean, a lot of attention to intricate shapes was developed.
The original design was created using C4D, the design can be animated using procedural elements. For instance the string on the racket animates to fill the loop area. All elements can be edited individually to support a desired design.
I recommend hiding elements while editing and animating the file, since the robustness of the project can actually slow down the computer considerably.