We're living in a golden age when it comes to cinematic special effects, but no matter how good (0r bad in some cases) CGI can be, it will never be able to replace certain practical effects and the need for movie props. Sometimes rather than opting for a world to be made entirely in post production film makers will commission sets to be made on a miniature scale.
Proof of their effectiveness is that you probably didn't even realise that many of the movie scenes below were created using miniature models until now. The level of detail that goes into these models really is amazing.
The Lord of the Rings
The Grand Budapest Hotel
The Fifth Element
Escape from New York
Indiana Jones and the Raiders of the Lost Ark