Chapter 1 of Don Quixote de la Mancha - annotated .ibooks format
First published in 1605, Don Quijote is considered a classic work of Spanish literature. It can be difficult to understand, even for native speakers (think Shakespeare for hispanophones). This version from Lingo Classics offers constant help and explanations in the margins and between the lines, with in-text links to further explanations.
You'll get a 8.4MB .IBOOKS file.