The moon looks larger when it’s near the horizon than it does when it is high in the sky. Sometimes, for example at this NASA website, this is phrased so as to imply that the view on the horizon is the one that’s illusory.
I once had the privilege of seeing this “illusion” in full force. I was walking down a tree lined city street, with the moon on the horizon surrounded in my visual field by trees and houses. The moon looked positively enormous – far larger than anything I’ve ever seen up-close and personal. Since I’ve walked around it a lot, let’s say the biggest thing I’ve seen up close is my city.
Guess what? The moon is far larger than an entire city. With proper cues available to clue the visual system in, this becomes more apparent.
It’s not always the grandiose view of an object that is illusory. Sometimes it’s when we see something as small that we are misperceiving it.