Prinz Eisenherz is the last of a royal line -- the blue-blooded gay bookshop -- having opened in 1978, it's one of the oldest survivors of its kind in all of Europe. Named for the German version of hairstyle-inspiring comic hero Prince Valiant, Eisenherz offers an impressive selection of LGBT lit, nonfiction, photo books, and DVDs. There's a large English language section, and the requisite array of international queer mags. As one might expect, the shop also hosts periodic readings and other gay events.