Travels into Several Remote Nations of the World, in Four Parts. By Lemuel Gulliver, First a Surgeon, and then a Captain of Several Ships, better known simply as Gulliver's Travels (1726, amended 1735), is a novel by Irish writer and clergyman Jonathan Swift, that is both a satire on human nature and a parody of the “travellers' tales” literary sub-genre. It is Swift's best known full-length work, and a classic of English literature.
In it's time posing as a traveler's log, it is actually a highly political and satirical work. So much so, that is outright “in your face” yet there are people even today who still manage to write it off as a children's book.
As a free ebook: http://www.gutenberg.org/ebooks/829
As a free audio book: http://librivox.org/gullivers-travels-by-jonathan-swift/