IMG_0306 - The concrete dome is a 40 m diameter hemisphere, the largest unsupported dome in the world.
IMG_0307 - The Pantheon has survived because it was consecrated as a Catholic church in the 7th century.
IMG_0309 - The hole cools the building, and lights it, especially the front door at noon on April 21.
IMG_0310 - The floor has 22 holes to drain water from roof hole.
IMG_0311 - Marble was imported from Greece and Turkey, including the 13m solid columns.
IMG_0313 - After conquering Egypt in 30 BC the Romans brought many obelisks to Rome. 13 remain.
IMG_0314 - These posts can be lowered into the ground remotely from emergency vehicles.
IMG_0317 - The old and the new, side by side, in Rome.
IMG_0320 - The Fountain of Four Rivers in Piazza Navona, for the four continents then familiar, by Gian Lorenzo Bernini.
IMG_0321 - The Piazza Navona started as a 15th century market on the site of the first-century Stadium of Domitian.
IMG_0322 - Fountain of Neptune. This piazza was developed about 1650, by Innocent X's Pamphilj family who lived there.
IMG_0325 - The ruins of the Stadium of Domitian in Piazza Navona can be visited 4.50 meters below the modern piazza.