Caroline C.
Yelp
I've been a reader and writer for, well, many years, and hands down this is the best book store I have ever been to, anywhere. They have the most unusual, worthwhile, amazing books--not only in the bindings and illustrations, but in the subject matter, rareity, etc.
I picked up an illustrated guide to 19th century illnesses, it is gorgeous, three chapbook style poetry books of "micro poems" in Spanish that are hilarious and irreverent (probably my two favorite descriptors in life), and an amazing illustrated copy of Alessandro Baricco's "Silk" in Spanish (Seda). Incredible. It made my trip to Madrid completely worthwhile.
Another worthwhile mention is the graphic novel style biography of Egon Schiele I spotted!