Established in 1914, the city's archives comprise millions of maps, drawings, prints, books, photography, and film about Amsterdam; a staggering 35 km worth, the biggest in the world. But (like the Rijksmuseum), there's a manageable highlights taster with 300 of the "most attractive, unusual, valuable, and moving" items on permanent display in the Treasury, former bank vaults that look like the tomb of an Egyptian pharaoh. The epic checkerboard building, completed in 1926 and named in honor of its theosophist architect Karel de Bazel, is also fascinating and infused with its creator's religious beliefs. In theosophy, a building is an art form that can express a higher message using mathematical principles to achieve total harmony. Have deep thoughts over lunch in the café or browse the excellent on-site bookstore, which sells every available Amster-relevant publication. The additional exhibitions (for which there is usually a small charge) are also terrific.