Founded in 1884 inside a 16^th century building, Beyazıt State Library, one of the oldest and largest libraries in Istanbul, underwent an important restoration. A reorganisation of the library space introduced a public flow through the library, from the square to the backyard, passing through spaces devoted to the display of over 25,000 rare manuscripts and reading rooms grouped around the courtyard. The existing 1980’s concrete roof, covering the courtyard, was replaced with a new structure, which filters light and provides a controlled atmosphere. The Library, now open 24/7, hosts exhibitions and cultural events during which the public can admire the Byzantine remains that were uncovered during the work.