Not the biggest, cleanest, most historied, or easiest to find used bookstore but not many are like Brattle. The selection covers every subject, genre, and time period. The rows are tight, and the books are cheap--between 5-10 for HC and 1-6 for PB. And then there's the special collection that I can't offer more insight into than the knowledge that they have one. Maybe after Grad school I'll walk by. Next to the 3 stories building filled with volume after volume, is a parking lot lined with bookcases that get covered at night. And on nice days the staff, mostly knowledgeable and of varied temperment, wheel out 15-20 librarian carts with even more books to tempt you. The books out side are discounted, probably to make up for the lack of any orderout there. If you know what you want, head inside, but for those of you that don't mind a day in the sun waiting for something to catch your eye, stay outside. If you're like me you'll leave with a bag full of books, none of which include what you thought you were going for in the first place. Before you leave take a look up on the walls on either side of the outdoor lot and the various portraits of literary figures, both antiquated and contemporary, each portrait with its our style, usually a visual companion of the particular author's work.A must see for any Bibliophile in Boston.