Yet there's one place the 20-year-old tennis superstar's journeys have never taken her — the region devastated 21 years ago by the Chernobyl nuclear reactor disaster.

Sharapova's mother, Yelena, was pregnant with her only child when the plant in Ukraine exploded and spewed radioactive clouds over the western Soviet Union and northern Europe.

"A lot of families were moving, but not a lot of them could because they didn't really know where to go," Sharapova told The Associated Press. "My mom's dad happened to be working in Siberia, so that's why we had a sense of direction."

Sharapova's father, Yuri, and her mother fled the city of Gomel in Belarus — about 80 miles north of Chernobyl — shortly before she was born in Nyagan, Siberia, exactly a year and a week after the explosion.

Gomel was one of the areas most affected by radiation. Sharapova said she still has family there, including grandparents.

Sharapova started hitting tennis balls at age 4. Two years later, she was discovered by Martina Navratilova at a Moscow exhibition. At 9, Sharapova and her father moved to Florida, beginning a two-year separation from her mother because of visa restrictions and limited finances.

She's never forgotten her roots.

In 2004, Sharapova won the season-ending WTA Championships and received a car worth more than $56,000. She donated the money to those affected by the Russian school hostage crisis in Beslan in which 334 people died, more than half of them children.

In February, when Sharapova was appointed an ambassador for the U.N. Development Program, she donated $100,000 to help recovery in the Chernobyl region.

Goodwill ambassadors try to draw attention to the plight of some of the world's poorest spots. Sharapova, who has earned more than $9 million in career prize money, has a two-year contract with the UNDP that pays her a symbolic salary of $1 a year. Goodwill ambassadors pay their own way on trips.

"They wanted me to work with them because they felt like people in those areas didn't really feel like they had a chance to survive," Sharapova said. "They wanted me to help raise the awareness that by building schools, hospitals, cleaning the air that there is pride and a side they can head towards instead of thinking all those negative things."

Her trip to Chernobyl will last just a few days.

"Unfortunately, I have about 28 days a year for the work that I do and for the sponsors, for the photo shoots and the visits," she said. "Time is very, very limited."

Sharapova won her first title of the season a week ago near San Diego. During the tournament, she met with a group of Russian children visiting the United States.

Their trip was sponsored by The Children of Chernobyl, a nonprofit group that brings healthy children from Belarus between ages 8 and 12 to America for a six-to-eight week visit. They are placed with host families and the children receive free medical, dental and eye care treatment.

Upon meeting Sharapova, some of the families asked what advice she could give the children.

"It's tough because most of them don't have any parents, and what's really helped me in my life was having my mom and dad be so supportive and around me," she said.

Despite her Wimbledon and U.S. Open titles and No. 2 world ranking, Sharapova didn't expect the children to know who she was.

"They had all these questions lined up for me. The kids are pretty young and the questions they were asking me were so mature and so beyond their years," she said. "This young kid asked me how I wanted to raise my children. I was like, 'Geez, you're a kid yourself.' It was very strange.' "

The children knew only rudimentary English phrases, like 'How are you?,' so they questioned her in Russian and Sharapova responded in her native language.

Hearing the kids squeal about their trip to Sea World brought back memories. As sophisticated as Sharapova comes off in photo spreads and on red carpets, she says she acts like a kid away from the court and cameras.

"I still love things that you don't even need to pay for," she said. "Going to the beach and being around five of your friends and having a good time means so much more than going out and spending hundreds of dollars. It did make me realize that, 'Wow, all these small things are making them happy.' "

Sharapova is to begin her U.S. Open title defense Aug. 27. She withdrew from the semifinals of last week's tournament in Carson because of a leg injury. She said she plans to compete for another seven years.

"I have so many other things in my life that I want to try and do," she said, ticking off marriage and children among her goals. "I'd love to open a tennis school for children in my hometown of Sochi."

Sharapova said she recently read a book about Africa, and it, along with her charity work, has helped expand her world of forehands and backhands.