Bernini's first work at St. Peter's was to design the baldacchino, a pavilion-like structure 30 metres (98 ft) tall and claimed to be the largest piece of bronze in the world, which stands beneath the dome and above the altar.
Michelangelo devised a monumental wide-ramped stair (the cordonata), gradually ascending the hill to reach the high piazza, so that the Campidoglio resolutely turned its back on the Roman Forum that it had once commanded. It was built to be wide enough for horse riders to ascend the hill without dismounting.