The Capitolium or Capitoline Hill between the Forum and the Campus Martius, is one of the Seven Hills of Rome. The hill was earlier known as Mons Saturnius, dedicated to the god Saturn. The word Capitolium first meant the temple of Jupiter Optimus Maximus later built here, and afterwards it was used for the whole hill (and even other temples of Jupiter on other hills), thus Mons Capitolinus (the adjective noun of Capitolium). In an etiological myth, ancient sources connect the name to caput ("head", "summit") and the tale was that, when laying the foundations for the temple, the head of a man was found, some sources even saying it was the head of some Tolus or Olus. The Capitolium was regarded by the Romans as indestructible, and was adopted as a symbol of eternity. By the 16th century, Capitolinus had become Capitolino in Italian, and Capitolium Campidoglio. The Capitoline Hill contains few ancient ground-level ruins, as they are almost entirely covered up by Medieval and Renaissance palazzi (now housing the Capitoline Museums) that surround a piazza, a significant urban plan designed by Michelangelo. The word Capitolium still lives in the English word capitol, and Capitol Hill in Washington, D.C. is widely assumed to be named after the Capitoline Hill. The Capitoline Museums (Italian: Musei Capitolini) is a single museum containing a group of art and archaeological museums in Piazza del Campidoglio, on top of the Capitoline Hill in Rome, Italy. 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. The museums are owned and operated by the municipality of Rome. The statue of a mounted rider in the centre of the piazza is of Emperor Marcus Aurelius. It is a copy; the original being housed on-site in the Capitoline museum. Opened to the public in 1734 under Clement XII, the Capitoline Museums are considered the first museum in the world, understood as a place where art could be enjoyed by all and not only by the owners.