Why are ancient buildings still standing 1500+ years later, but some buildings built like 30 years ago are falling apart?

Question

Why are ancient buildings still standing 1500+ years later, but some buildings built like 30 years ago are falling apart?

In: Other

Answer 1

Keep in mind not all buildings from long ago are still standing. It’s selection bias: we only see the ones that stand.

But a big mass of limestone like an Egyptian pyramid has a good chance to stay standing because it’s a stable shape. The ones that stand had shallow enough slopes on their sides that they can’t fall over like an obelisk can.

There were other pyramids with steeper sides that didn’t do as well.

Stone and earthen structures also tend not to burn down. A pyramid in Giza was the tallest building in the world for thousands of years. Then someone build a wooden church tower in England that surpassed it. Within 200 years, that tower burned and the pyramid was the tallest building again.