Amid the rolling hills of Jiangzhou in South Korea,

there is a structure, a perfectly round tower,

that's tapered with a square frame perched on top.

It was built with 362 big granite stones, the same number as there are days in the lunar year.

This structure is an observatory, a way for people to examine the stars and planets.

And this one is one of the world's oldest.

It was built by Queen Sandak of Shilla,

a clever queen from an ancient Korean kingdom. And for her, the stars held a special significance, but we'll get into that later.

Queen Sunduck lived 1,400 years ago, so long ago, in fact, that we don't have very much

information about her life.

Perhaps there were more detailed records at the time,

but those have been lost over the centuries.

So we do what storytellers have always done.

We fill in the details with our imagination.

The stories that people tell about kings and queens, inventions and journeys, shift and evolve over time as new people tell them.

The story that someone tells about Queen Sunduck may sound very different,

100 or 1,000 years from now.

But this is the story

we are telling about her right now.

Queen Sunduck was the second daughter of a king who had no sons. She grew up in a palace with long wooden corridors and curved tile roofs.

She learned history and art and literature and the sayings of the Buddha.

She liked dipping her brush into the pool of deep black ink on her desk,

...