Governments draw borders. Governments manage borders. But humans live inside them. From the North Pole to the northern shore of Africa to the Himalayas of Nepal, the lines we’ve used to apportion the planet play a decisive role in the past, present, and future of billions.

Every border has a different origin story and a different character. Borders can encourage exchange or instigate violence. They can provide refuge, or they can criminalize those who cross them. Borders symbolize a nation’s anxiety about the world, and as political leaders regulate the lines on the map, there will always be human stories at the mercy of those choices.

I’m Johnny Harris, a journalist at Vox. I spent a good portion of this year meeting and listening to the people living on the front lines of international relations, where the decisions made by governments play out on a human scale. The result is a series of six documentaries — the human stories behind lines on a map.

If you want to know a country’s deepest fears, look at its border.