Campidoglio, Rome, Italy. The Italian name for the Capitoline Hill, between the Forum and the Campus Martius, one of the seven hills of Rome. By the 16th century, Capitolinus had become Campidoglio. The English word capitol derives from Capitoline. The Capitoline contains few ancient ground-level ruins, as they are almost entirely covered up by Medieval and Renaissance palaces (now housing the Capitoline Museums) that surround a piazza, a significant urban plan designed by Michelangelo.