The historic seats of the museums are Palazzo dei Conservatori and Palazzo Nuovo, facing on the central trapezoidal piazza in a plan conceived by Michelangelo in 1536 and executed over a period of more than 400 years. The history of the museum can be traced to 1471, when Pope Sixtus IV donated a collection of important ancient bronzes to the people of Rome and located them on the Capitoline Hill. Since then, the museums' collection has grown to include many ancient Roman statues, inscriptions, and other artifacts; a collection of medieval and Renaissance art; and collections of jewels, coins, and other items.