Explore Topkapi Palace, once the administrative centre and home to Ottoman rulers for over 400 years, with skip-the-line entry. The former residence of over 25 sultans, it is now a large museum and library. Inside, you'll find the Byzantine Church of Hagia Eirene, converted to an armoury inside the First Courtyard; an exquisite Chinese porcelain collection in the kitchens in the Second Courtyard, regarded as the third most valuable in the world; the harem, home to the royal family; and more.