#443 – Gregory Aldrete: The Roman Empire – Rise and Fall of Ancient Rome

10106.208 - 10126.722 Gregory Aldrete

And then as you get further up the dome, it gets narrower and narrower, and they mix in different types of rock. So at the top, you're using pumice, that very light volcanic stone. So where you want it to be light, it's light. And it's here 2,000 years later. I mean, look around you. How many buildings that we're building now do you think are going to be here in 2,000 years? I suspect not many.