[Paal Gulli]

Probably the most famous concrete building on the planet, the Roman Pantheon.

To prevent the walls (and the dome) collapsing under their own weight, they used lighter and lighter aggregate the higher the walls got. At the base they used a limestone called travertine. The aggregate in the top level is volcanic pumice, which weighs about the same a popped popcorn.

At upper left, you can see brickwork arches incorporated into the walls, which they used to transfer the load onto reinforced columns so the concrete beneath the arches could be less robust.

Built in 609 AD, it remains the largest unsupported concrete dome on earth.

[Steely Tom]

Probably the most famous concrete building on the planet, the Roman Pantheon.

The words on the architrave are essentially an advertisement.

[OldHarbor]

The Norfolk Scope.

The arena was designed by Italian architect/engineer Pier Luigi Nervi

Featuring the world's largest reinforced thinshell concrete dome (though eclipsed by the Seattle Kingdome from 1976 to 2000)

[Chicory]

Your explanation of the brick arches is so cool! I had no idea there was a functional reason for them, although now that I know about it, it makes total sense!

Thank you!