Pantheon

Nearly done, might add a few things here and there but pretty much complete.
The 4,535 metric tons (4,999 short tons) weight of the Roman concrete dome is concentrated on a ring of voussoirs 9.1 metres (30 ft) in diameter that form the oculus, while the downward thrust of the dome is carried by eight barrel vaults in the 6.4 metres (21 ft) thick drum wall into eight piers. The thickness of the dome variesfrom 6.4 metres (21 ft) at the base of the dome to 1.2 metres (3.9 ft) around the oculus.[34]