Leonardo da Vinci made this one around 1502 — while stuck on the ground.

How?

When infamous Italian politician Cesare Borgia brought Leonardo da Vinci — the guy who

drew this portrait — to the city of Imola, it was as a military engineer.

He'd already established a good military reputation — and painted several famous works.

When Leonardo was installed at Borgia's newly acquired fort, one of his duties was

to help Borgia learn the territory.

At the time, a map like this one was the standard — a birdseye or hillside view.

Mythical creatures often popped up — not great for military operations.

The perspective also only showed some buildings, blocking the view of other ones.

These maps could be beautiful.

But they lacked proper shape and scale And highlighted landmarks' beauty at the

expense of clarity.

Leonardo needed to show Imola as an “ichnographic” map — an idea that

Vitruvius — a Roman engineer and the guy who inspired this — had described.

In practice, it's a map where everything looks like you're directly above whatever

you show.

It gives you a clearer picture.

Look at the fort.

In Google Maps, the shadow effects change a bit, but the fort's perspective fundamentally

stays the same.

That's similar to a real view from far above,

where distance reduces the effects of shifting perspective.

But Leonardo didn't have a satellite to get up that far.

His plan of Imola was a feat of symbolic imagination.

And he had to make it accurate.

Based on sketches, previous work, and the design of his Imola map, we can guess at how

Leonardo made it.

He probably used a type of disk that could measure degrees and had a little pointer to

mark the angles of streets in relation to a stable point, usually North.

He probably used a compass to record the orientation of the town's surrounding walls.

He did this at every turn, which helped him accurately translate the walls onto paper.

Note the circular shape here, overlaid on the map.

To establish scale, Leonardo also needed to measure the distance between all of these angles.

He probably paced this out by foot, or maybe using an odometer, with wheels that turned

gears that measured distance by dropping a ball into a bucket at set intervals.

With the angles and distance together, he could create a plan — hundreds of years

before anyone could check if he got it right.

This stunning map from 1551, by another Leonardo, shows the potential Leonardo da Vinci's

method had.

All these early ichnographic maps have asterisks - this one was spotted with its own inaccuracies

and artistic flourishes, a reflection of the scope of the project.

In turn, Leonardo's Imola had quibbles too — he probably used parts of previous surveys

and other artistic techniques.

It also appears that he measured the town's walls precisely, but took more liberties with

the angles in the town's interior.

But even with artistic license, this remains a map of more than a fort and town.

It's a transition from a geography of myth and perception to one about information, drawn plainly.

It's a map of Imola, but in the early 1500s, it was a map of the future, too.

Hey, if you're curious about this video or any of the videos in Almanac or Overrated,

I'm going to be doing a live Q&A in the Videolab where we answer a ton of questions

about that and the Vox process.

The nerdier your questions the better — I hope to be asked about my favorite Adobe Premiere

shortcut and also Leonardo's odometer.

So, if you have those questions drop them in the comment below and head over to vox.com/join

and you can ask me directly on the stream.

This is a stream thing I'm doing with my hand.

Pretty cool.