The Palace Museum, former home to the 24 Ming and Qing emperors, is also known as the Forbidden City. Completed in 1420 during the Ming Dynasty, it occupies a total space of more than 720, 000 square meters. Apart from the complex of immovable palace buildings, the Palace Museum houses over 1.5 million items or sets of relics. Over 8,000 of them are designated as first-class relics. They fall into the following categories: paintings, calligraphy, rubbings from tablets, inscriptions, sculptures, copperwares, porcelain, textile or embroidery, jade or stone wares, gold or silver wares, jewelry, lacquerworks, enamel wares, carvings, miscellaneous handiworks, stationery, daily appliances, clocks and instruments, imperial seals and certificates of the conferring of titles, religious relics, weapons carried by guards of honor, ancient books, and foreign relics. The museum is open to the public all year round.