In FINDING HIDE & SEEK with Hamilton Morris, we learn about a painting by Pavel Fyodorovich Tchelitchew that has gained a cult following of people who love to stare at it while taking Peyote. Tchelitchew, a Russian surrealist painter, created Hide and Seek in 1940. The painting is currently owned by MoMA. Similar to an experience of pareidolia, the more one looks at this piece of art, the more you'll see camouflaged faces suddenly become distinct from the colorful background.
This painting is so trippy on its own, that I can't even imagine what adding psychedelics to the mixture would be like. Hamilton has a similar opinion and explains that people like to "take peyote and look at this painting, but I don't think that's even necessary."
(Front page image of Hide and Seek at MoMA for visual identification of the object of the article. The entire article is devoted specifically to a discussion of the work.)