Found­ed, accord­ing to leg­end, by Romu­lus and Remus in 753 BC, Rome was first the cen­tre of the Roman Repub­lic, then of the Roman Empire, and it became the cap­i­tal of the Chris­t­ian world in the 4th cen­tu­ry. The World Her­itage site, extend­ed in 1990 to the walls of Urban VIII, includes some of the major mon­u­ments of antiq­ui­ty such as the Forums, the Mau­soleum of Augus­tus, the Mau­soleum of Hadri­an, the Pan­theon, Trajan‘s Col­umn and the Col­umn of Mar­cus Aure­lius, as well as the reli­gious and pub­lic build­ings of papal Rome.