Real World Parabolas

There are many parabolas in the world, such as the Gateway Arch and the golden arches in a Mcdonald's sign. But the one i am going to inform you about is the Colosseum in Rome, Italy.

I know that the whole structure is not a parabola but if you look closely at the windows or the building then you see the parabola(s). The Roman Emperor of 69 AD, Vespasian, was behind the idea of building the Colosseum. It used to be called the Flavian Amphitheater. It is made up of concrete.