I would put them in Parks, since they are clearly engaged in leisure and entertainment. It would also allow you to build more than one. The Monument/Unique Building button should be reserved for things bigger (but not more important) than your masterpiece.

There is no better category, All buildings make no sense with a citizen object :-)

Okay. Consider putting it in a different category, if anything makes sense.

Its a building , because the CAL mod works only for buildings. When I save it as a prop and put the animation file with it nothing will happen.

@turtleshroom yes it is a prop. But magically it has animation with CAL.

Why are these listed as Unique Buildings? They should be Props.