Over the years, I've certainly heard of the 2nd century work, A True History, by Syrian author Lucian of Samosata. But I've never heard a Cliff Notes-like summation of what this novella, considered by many to be the first work of sci-fi, was actually about.
Sailing ships hurled to the moon? A war between the Moon and the Sun with fighters riding on the backs of giant space birds, ants, spiders, and fleas? Combatants wielding giant asparagus spears and getting trapped in colossal space cobwebs? Sounds like an entertaining and surreal read. But, as Austin McConnell points out, this spoof of the popular travelogs and debate narratives of the time is so full of 2nd century satirical references and inside jokes, much of it sails right over the heads of modern readers.