The Mausoleum of Constantia ~The mausoleum was later consecrated as the Santa Costanza church. Constantia (sometimes called Constantina) was the daughter of Emperor Constantine and his second wife Fausta and was never actually canonized.
Pantheon | detail of coulmns at the portico, Pantheon, Rome, AD 127. They were made by Greek marble cutters. The marbles also were imported from Greece.