Pantheon Roof

Probably the most amazing artefact of the ancient world I have ever seen anywhere, the Pantheon started life as a Roman temple to all the gods and became a Christian church in 609 AD. It is still splendid today, 2000 years old and going strong. I first visited it when I was in my mid-teens and it's one of those places in the world (like Mono Lake and Yosemite Valley) always guaranteed to awe me no matter how many times I visit.