I recently learned of the Lalibela churches in Ethiopia.
The churches were somehow built between the 7th and 13th centuries and they are still standing today.
Instead of building churches on top of the ground, they were built into the ground to top Muslim invaders from spotting them.
They’re all built from a single rock.
Exactly how they did this is not clear but it was carved almost entirely with handheld chisels.
A single rock and some chisels and they’ve stood for 700+ years.
I found out about Lalibela reading this book.
