One of Baltimore's hidden treasures, the 1866 Peabody is an architectural gem with the cast-iron balconies soaring five levels to a shining glass ceiling. It's an academic gem as well -- the resting place of 300,000 volumes, mostly rare books, with some dating to when the printing press was new. Philanthropist George Peabody provided the funds to build this magnificent "cathedral of books" and ordered that it be filled with the best works on every subject. Literary exhibits change regularly in an adjacent gallery.