The Library's Geography & Map Division has custody of the largest and most comprehensive cartographic collection in the world, including more than 5 million maps, 100,000 atlases, 8,000 reference works, over 5000 globes and globe gores, 3,000 raised relief models, 130,000 plus microfiche/film, and a large number of cartographic materials in other formats. Many of these materials have been digitized and are available online. You may search for maps from the Ottoman Empire at Library of Congress Digital Maps. Materials that have not been digitized are available in the Geography & Map Reading Room.