La Montana Soberana is a free 100 page megadungeon in Spanish.
"I don't know Spanish," you say, well, it's released in a word document as well as PDF, so you could presumably copy and paste that into a translation program. (I can't speak it, but I can read Spanish fairly well.)
Actually, the website for the Spanish Mentzer clone, Adventures in the East Mark has a ton of free modules. While they are in Spanish, the monster stats and what not are pretty much the same. The only confusing thing is hit dice, which is "Dados de golpe", and armor class is reversed (CA), as it is "Clase de armadura"