This is damn interesting.

Headphones recommended.

It was the middle of a cool September night in Munich, Germany.

The year was 1939.

In an otherwise unoccupied auditorium, a man knelt on hands and knees chiseling a square

hole into a large stone pillar. The lights were all turned out, but a small flashlight

dimmed to the handkerchief provided a pallid little puddle of light. The man had wrapped

his chisle in cloth to quiet his hammer strikes. Whenever there was some unexpected sound,

he froze.

Whenever a truck rumbled past the building, he seized the opportunity to chisel more vigorously.

It was exceedingly tedious and slow work.

The man working there was a 36-year-old German handyman named Georg Elzer.

But handyman isn't exactly the right word.

In his three-and-a-half decades, he had cultivated many skills, including clockmaking, cabinet building, master carpentry, and stone quarry.

And the task at hand required all of his diverse expertise.

The room where he worked was a beer hall in Munich, known as the Berger Browkeller,

and it already had an interesting role in history.

In Germany, it's a tradition for citizens to crowd into such beer halls to engage in lively political and social debates,

and to sing beer-infused trinklider late into the night.

And in this particular hall, just a few feet from where Elzer was chiseling his whole,

just 16 years earlier, a young Adolf Hitler had stepped up to the podium to convince a crowd

of citizens to support his attempt to overthrow the kaput German government.

...