London (CNN) -- Photographer Rania Matar moved from Lebanon to the United States at the age of 20.
More than two decades later, her experience as a teenager and young woman in both countries has inspired her to photograph more than 300 American and Middle Eastern girls in their bedrooms.
The result, an exhibition called "A Girl and her Room" opening Friday at The Mosaic Rooms in London, shows American, Lebanese and Palestinian teenage girls in their most personal spaces. It includes girls in Palestinian refugee camps.
Matar said: "Some of the girls you wouldn't know where they were from unless you read the captions.
"The American girls tended to have more freedom and messier bedrooms. Their rooms were cocoons for them.
"The Middle Eastern girls more often shared their rooms, or it was more of a family space. However, even in the refugee camps the girls had some space of their own, even if it was just a closet."
Despite the differences, it was their similarities that most struck Matar, a mother-of-four living in Boston, Massachusetts.
"All these girls are trying to find who they are. At that age they are all going through a defining moment in their identity. Their body language had a lot of similarities," she said.
Matar's project began two years ago with photographs of her own daughter Lara, now 17.
"She used to be such a tomboy and I could see her completely transforming. I became interested in photographing her when she was with her friends," said Matar.
"However, she wasn't the same person with her friends and I realized I would rather photograph each girl on their own. Originally I asked the girls to choose where they would like to be photographed and a couple chose their bedrooms.
"I realized that was what I wanted because their bedroom reflected who they were and they could be completely themselves there."
The project rapidly expanded from American girls Matar knew, to those she stopped in the street and eventually to those on the other side of the world.
"I grew up in Lebanon and moved to the U.S. when I was 20, so these were the worlds I knew when I was growing up," she said. "I have these two cultures in me. It was a personal project."
Matar ran a photography workshop for girls in a refugee camp in Lebanon and decided to include some of her students in the project.
"As they were taking photography classes it was a good experience for them to be on the other side," she said.
Matar said she found working in refugee camps particularly moving because she had grown up nearby but in a very different world during Lebanon's civil war.
She said: "I grew up in Lebanon but had never been to a refugee camp. I realized there were five minutes by car from where I used to live, but it was a world apart from the westernized Beirut that I grew up in.
"At first I was shocked by the poverty, but eventually I saw the beauty and humanity there. The kids were an inspiration to me. They are not asking for $80 soccer shoes, but playing soccer in their flip flops and bare feet. It was very humbling.
"These are just teenage girls like any other girls. There was one who had Hannah Montana all over her walls."
Despite having two sons -- one of them a twin brother to Lara -- Matar has kept her focus on girls.
"I wanted to do something personal to me, and I was once a teenage girl so I could relate to girls at that age," she said.
"Besides, my son told me if I took pictures of any of his friends, he would kill me!"
Matar has recent signed a contract for a book of "A Girl and her Room," expected to be published in spring 2012.
She currently has four pictures displayed as part of an exhibition called "Rebirth" at the Beirut Exhibition Center, but hopes to bring the full exhibition to Lebanon when the book is released.
"Lebanon has always been interested in art, but there was a war on. Now, culture is really taking over again," she said.
"A Girl and her Room" is at The Mosaic Rooms in London until July 23 as part of the Shubbak, a new festival of contemporary Arab culture taking place in the city throughout July.