The girls giggle in their classroom. They laugh and joke with each other as they mop the floors and clean the bathrooms of the large, comfortable house where they live.
Juanita, who is 14, arranges her teddy bears on her bunk bed.
"I like it here," she says of the shelter for homeless girls run by the Salvation Army on the outskirts of Costa Rica's capital. "It's much prettier than the streets."
Just six months ago, Juanita was a troubled runaway, standing on a darkened corner in San Jose's tourist district, offering to have sex with foreign men for money.
Children's advocates say Central America has become a hub for the sex-tourism industry, fed by graphic sites on the Internet that advertise an anything-goes atmosphere, cheap travel costs and crackdowns in better-known sex tourism centres such as Thailand and the Philippines.
Exploitation of children, both boys and girls, is the seamier side of the trade.
As Central America's most prosperous, stable nation and its top tourist destination, Costa Rica has fallen under the international spotlight for the problem. Prostitution is legal and regulated by the government here, but only for women 18 years of age and older.
"Pedophiles look for three things -- anonymity, poverty and impunity," said Bruce Harris, director of Latin American operations for Covenant House, a private group that works with troubled teenagers in several North American cities, as well as in Central America. "They find them here. These children are desperate and vulnerable, and the government has not assumed its responsibility for taking care of them."
Mr. Harris cites a U.S. State Department report that estimates as many as 3,000 underage children may be sexually exploited in Costa Rica. A United Nations committee has also expressed concern, he says.
Costa Rican officials say the numbers are a gross exaggeration.
"To give that type of number is irresponsible," said Lillian Gomez, the country's top prosecutor for sex crimes. "It's clear the problem exists, but not in that dimension."
Mindful of their country's reputation as a family-oriented tourism gem, government officials have taken steps to combat the problem.
Laws have been passed outlawing sex with children, and perpetrators face prison terms of up to 10 years. Ms. Gomez has been promised increased resources, although she has yet to see any.
The government has also funded a national Save-Our-Children advertising campaign, featuring television and print ads reminding people that children are the nation's most valuable resource. Brochures will be printed for distribution to arriving visitors, warning that sex with children is unlawful, while government Internet sites pushing Costa Rican tourism will do the same.
"We don't want those kinds of people coming here, and we don't want our country known for that type of activity," said Costa Rica's Tourism Minister Walter Niehaus. "We take this very seriously."
Police have also cracked down on San Jose's red-light district. While visitors can still find legal prostitutes in the bars and casinos that cater to tourists, the bands of underage boys and girls who only a few months ago roamed the district and brazenly propositioned foreign men are gone.
Several well-publicized raids have swept them from the streets, hampering the operations of private homes that served as brothels.
But underage prostitutes are still available. Visitors need only ask a taxi driver in order to be taken to a private home where girls under the age of 18 make themselves available, at times for as little as $25.
Mr. Niehaus says he'll soon start a program in which taxi drivers will display stickers warning passengers not to ask for help in finding young girls for sex.
Mr. Harris says government efforts are inadequate, aimed more at improving Costa Rica's image than helping the children.
"It's very frustrating," he said. "Until we see a big sign at the airport showing the pictures of foreigners behind bars instead of this dancing around to protect the country's image, nothing will change."
Jorge Vargas, director of children's programs for the Salvation Army and a former governor of San Jose province, says the problem is part of a wider crisis of delinquency and drug-use among Costa Rica's young people.
"Our society has lost its values," he said. "We need a change in attitude by the public."