The Clementinum is a historic complex of buildings in Prague, Czech Republic. It is home to the National Library of the Czech Republic, and the site includes the famous Baroque-era library, the Clementinum Library. The library was founded in 1622 and has one of the most beautiful Baroque interiors in Europe. It contains over 20,000 books, including a collection of theological works from the 16th and 17th centuries, and is also home to two globes by the famous Czech astronomer and cartographer Václav Hollar. Visitors can take guided tours of the library and admire the stunning frescoes and ornate decorations. The Clementinum complex also includes several other noteworthy buildings, including the Astronomical Tower, the Mirror Chapel, and the Baroque-era Church of St. Clement.