When Rania Matar was a teenager in Lebanon, her country was ensnarled in a long and bloody civil war.But her bedroom betrayed little of what was going on outside — in typical teenage fashion, she papered the walls with posters of rock stars and pictures of fast cars."There was something very endearing about that," she recalled.Years later, when her daughter and friends entered adolescence, Matar, by then a photographer living in the United States, took an interest in documenting their lives. When she started using their bedrooms as backdrops for the sessions, things felt oddly familiar."I realized 25 years earlier, I was like those girls, in a different country and different culture, but there was something universal about being a girl that age," she told Refinery29.Matar decided to broaden the project to the Middle East, taking portraits during her travels of teens in their bedrooms there. While each girl had her own style, a common thread emerged. These girls all chose to "express themselves in their bedrooms because this is where they live and they can control the space," she recalled.“Anytime you put the news on here, you’re going to hear something negative coming from the Middle East," she said. "But at the end of the day, these are girls going through the same transition at the same time. Some of them might be expressing themselves in a very similar way, others very different, but the universality of it was that they were all straddling that transition between childhood and womanhood, and experiencing with what it is."The portraits were ultimately made into a book, A Girl and Her Room. Matar has continued to focus on women, girls, and cultural identity; another book on girls on the brink of adulthood, L'Enfant- Femme, is set to be released this spring.Ahead, take a look inside the lives — and rooms — of teens in the United States and in the Middle East.