I was recent led to a fascinating website “Matte Shot – A Tribute to Golden Era Special FX” which displays matte paintings used in Hollywood movies. My favorite is this one which shows how the ballpark from the MGM musical Take Me Out to the Ballgame (1949) was really just a painting. Ah! The magic of the movies.

This one from Green Dolphin Street (1947) which won the Oscar for its mattes and miniatures:

You can see more here: http://nzpetesmatteshot.blogspot.com/2014/09/