This Art Nouveau building is UNESCO-listed and one of Zagreb's finest -- it's also home to Croatia's most important documents. The Archives' written holdings won't interest most English-speaking visitors, but architecture buffs from any country will be awed by the interior and exterior treasures concentrated in the stately building that opened in 1913. Both the lobby and atrium area one level up are adorned with brilliant mosaics, intricate ironwork, sparkling leaded glass, and lustrous marble. These spaces are also used for art exhibits, all secondary to their dazzling setting. Outside, the symmetrical park landscape is home to an Ivan Mestrovic masterpiece. Guided tours are required for admission.