A librería de viejo is a secondhand bookstore that specializes in selling used and rare books. These types of bookstores can be found all over the world, often in older or historic areas of cities. Librerías de viejo are known for their unique collections of books that may be hard to find in regular bookstores. Customers can browse through shelves of old and out-of-print books, magazines, and other literary treasures, making it a popular destination for book lovers and collectors.