When Malala Yousafzai turned 18, she opened a school for Syrian refugee girls, calling on leaders from around the world to provide “books not bullets.”

It was at 18 that Cleopatra became ruler of Egypt, in 51 B.C.E., and Victoria the queen of Great Britain, in 1837.

By the time she was 18, Britney Spears had had two No. 1 albums on the Billboard chart, and Serena Williams had won the U.S. Open.

Emma Gonzalez, 18 now, has become a global leader in the movement to end gun violence.

No pressure, right?

Eighteen is an age. But it’s also something more. It’s a moment, a rite of passage, a gateway to adulthood.

In the United States, 18 means you can finally vote, sign a lease on an apartment, obtain a credit card and buy a Juul.

In China and parts of Canada, 18 grants you entrance to a pub, while for most Israelis, it means a mandatory draft into the military.

By 18, one in five women across the globe will be married. Millions will enter college or university.

“This is 18” aims to capture what life is like for girls turning 18 in 2018 across oceans and cultures — in Mexico and Mississippi, Ramallah and Russia, Bangladesh and the Bronx.

But while girls have long been the subject of the photographer’s lens, they have far less often been behind it. So we asked young women photographers to document girls in their communities — taking the photos and conducting the interviews themselves. Each photographer was paired with a professional mentor to guide them through the process.

The result is a celebration of girlhood around the world — across 12 time zones and 15 languages, featuring 21 subjects and 22 photographers. (Yeah, it was a lot.)

We’re thrilled to present #ThisIs18 — a look at girls’ lives, through girls’ eyes.​​

—Jessica Bennett and Anya Strzemien