Favourite Weirdly Specific Cartoon Trope: The characters accidentally straightening the Leaning Tower of Pisa.
Alternatively: if it takes place in the past, the characters are responsible for making the tower lean to begin with.
Okay, but also consider:
-Characters accidentally knocking the arms off of the Venus De Milo statue/ knocking the nose off the sphinx
- Characters ending up as models for classical paintings and sculptures, typically the Mona Lisa, the Thinker, the Scream, or a Salvador Dali piece
-Characters actually making those artworks themselves, only for the famous artist to take all the credit for them
All classics.
characters seeing the mona lisa being painted and she has a huge smile but for whatever reason they cause her to only give a slight frown