The original building was designed by architects Peró and Torres Armengol and opened as the Teatro Gran Splendid in May 1919. Like much of the architecture from the period, the interior features lavish details such as a ceiling frescoespainted by the Italian artist Nazareno Orlandi and caryatids sculpted by Troiano Troiani. The transformation from theater to bookstore consisted of removing the cinema seating and installing rows upon rows of bookshelves. Customers wishing to curl up with a book have their choice of many chairs scattered throughout the store including the original theater boxes. The area behind the stage is now a café.
In 2007, El Ateneo Gran Splendid sold over 700,000 books and over a million people walk through its doors annually. In 2008, The Guardian places El Ateneo in the number two spot on its 2008 list of the World’s Ten Best Bookshops.