From the pristine Takoma courts at the northern tip of the city to the Congress Heights courts in the south; from Palisades in Northwest to the picturesque Anacostia courts in Southeast, many public tennis courts are in better shape than in decades.

But on recent sunny spring days, exactly six people were using the 20 combined courts at the four sites, and many more newly resurfaced courts across the city were entirely empty.

To be sure, a survey of the city's 247 public tennis courts was done on weekdays, when many tennis players are at work. It was also a time when schools were in session and children were unable to play.

Nonetheless, an aggressive tennis rehab program that has boosted nearly half of the D.C. courts into good or near-perfect shape has not produced a corresponding increase in tennis court use, according to tennis and recreation officials.

"As I drive around the city, I see a lot of courts with nobody there," said Rose Hobson, president of the Washington Tennis Association of the United States Tennis Association.

"Yes, I would have to agree that our courts are underutilized," said Drew Becher, associate director for operations at the D.C. Department of Parks and Recreation.

Despite the success of tennis stars Venus and Serena Williams, who have won 10 Grand Slam titles between them and are the game's most popular players, tennis has not taken off among D.C. youth.

Some of the public courts in the best shape charge fees: those at Hains Point, Rock Creek Park at Carter Barron, and the Southeast Tennis and Learning Center. (The Southeast center charges fees only for adults.) But there are also free courts in good condition, such as Kenilworth-Parkside, Langdon, Arboretum and Douglass. Some of them are frequently empty.

As a result, recreation officials have already worked with a private non-tennis foundation to turn two courts in Shaw into a skateboard park. Several other courts across the city are used as fenced playgrounds for young children who are playing tag and other games.

"Tennis is a big priority," said Becher. But he noted that other cities have turned vacant courts into "dog-friendly parks" where animals can run free, or into skateboard sites.

"It really goes by the use," said Becher, referring to the future of the city's courts, "and what the community wants."

Right now, Becher said, the city has a schedule for renovating more tennis courts that are cracked or weedy. "Coming up shortly is Fort Lincoln, Marie Reed, Benning Park and Ferebee. Next spring is Congress Heights, Fort Stevens, Deanwood, Barry Farm and Rose Park," he said.

Washington is a city rich in public tennis sites, but poor in funds to maintain them or to provide neighborhood instructional programs.

Nowhere is that more clear than in the schools. Dunbar High School, Backus Middle School, Evans Middle School, Patricia Roberts Harris Education Center: Those are just four schools where courts are overgrown with weeds, have missing nets and poles or are paved with what looks like the leftover supplies of a pothole crew.

"The school system has lost manpower because of the cuts over the years," said Allen Chin, director of athletics for the D.C. public schools. "Some, the recreation department will take care of. But [the facilities staff] focuses on fire code violations and internal maintenance."

Although Chin says D.C. public school students are commonly exposed to tennis in the elementary schools through physical education teachers -- many working with the United States Tennis Association -- he ranks the system's tennis program as only "fair."

The elementary and junior high programs rely heavily on charity and volunteers. "The Washington Tennis and Education Foundation handles the lower grades for us," said Chin.

The foundation, a philanthropic organization that raises money from the Legg Mason Tennis Classic, foundations and individuals, offers education and tennis programs in 23 of the city's 125 traditional public elementary and junior high schools.

The Washington Tennis Association is also actively working to introduce tennis into the schools.

One sunny morning last month, Bernard Wilson, a physical education teacher at Kenilworth Elementary, was out on the Kenilworth-Parkside courts, teaching 25 first- and second-graders to hit the ball. Wilson, who is in charge of the schools program for the foundation, makes tennis a regular part of his physical education classes.

He paces the courts with his 25 students. "Mr. Wilson. Mr. Wilson. Mr. Wilson. Mr. Wilson, I made the ball go waaay over to the other side," the kids shout.

"This is tennis, not baseball," he laughs as his young charges struggle to set up a volley.

At the upper school level, 12 high schools field tennis teams, out of 17.

"If we are going to grow the sport, we have to introduce kids to the game early," said Hobson. She not only has been working with physical education teachers in the schools but also has been trying to find volunteers for after-school and Saturday instruction.

"When you say the word volunteer, you would be surprised how many heads turn the other way," she said.

A requested list of D.C. Department of Parks and Recreation sites rolls out of the fax machine, listing literally hundreds of locations of tiny recreation centers, swimming pools, ballfields, picnic grounds, playgrounds and -- one of the largest categories -- tennis courts.

When the District emerged from bankruptcy in the 1990s and a trickle of money became available for recreational improvements, the department fixed up ballfields and tennis courts first.

About 90 tennis courts were resurfaced, and 25 ballfields improved. Michael Williams, interim chief of sports and fitness for the recreation department, said that, as a rule, the city estimates the cost of renovating each court at $25,000.

The city's investment in court repairs has not had the payoff some had wished.

Hobson said that the total number of tennis players in D.C. has grown by 10 to 15 percent over the past five years, but that more needs to be done to attract young people to the sport; hence her emphasis on schools.

In Washington, she said, the typical player is a black, well-educated person 25 to 40 years old, with a family. A seniors group is also very active. Shiloh Baptist Church of Washington has a strong tennis group, started in 1976, now 150 players strong.

Another tennis initiative is based in the new Southeast Tennis and Learning Center, a $5 million facility spearheaded by former D.C. first lady Cora Barry with 10 perfect courts and new classrooms with computers. It offers tennis and educational programs during the school year.

In the summer, 100 to 150 kids sign up for camp to learn tennis, according to Jeff Mays, 43, the assistant director. He said that on any given day about 70 children take after-school tennis lessons and participate in required academic classes. Other children come to the center strictly for the educational program, he said.

Although there are down times -- for example, now during final exams -- the Southeast program handles as many students as it can hold on a regular basis, he said, and is limited from further expansion by liability issues.

On a recent sunny Tuesday morning, the facility had one player. Arnold McKnight, the director, had come in on his day off to coach his 7-year-old son, Taylor, who is home-schooled.

H'Cone K. Thompson, 23, of Brookland, a high-ranking player in the Mid-Atlantic who coaches at the Washington Tennis and Education Foundation Academy, said tennis is a hard sell in the city. "It's like pulling teeth" to get people interested, he said.

Private groups and citizens have been pitching in for many years to help the city make the courts attractive to newcomers and veterans alike. "The department is very open to public-private partnerships," said Camille Mosley, the widow of Dwight A. Mosley, the former treasurer of the United States Tennis Association. When Mosley died of brain cancer in 1996, people wanted to help, but "they need to understand what they need to do. Some requests are so nonspecific," she said.

The Mosley Foundation helped pay for fixing up the five courts at the Taft athletic complex at 19th and Otis streets NE. The complex was renamed the Dwight A. Mosley Athletic Complex in his honor, although it is still called Taft on the city's official Web site.

Neighbors still pitch in to keep the courts clean, Camille Mosley said. A group is painting a mural on the backboard. "The people who live there know that that is important," she said, "and they are not going to mark it up."

Rose Hobson, Washington Tennis Association president, looks at a rusted net pole on weed-covered courts at Evans Middle School in Northeast. "We have to introduce kids to the game early," she says.Five-year-olds Maurice Gary, above, Allana Wright, below left, and Loreana Briscoe, below right, practice at Kenilworth-Parkside courts. Bernard Wilson, physical education teacher at Kenilworth Elementary School, teaches kindergartners and first-graders to play tennis at the Kenilworth- Parkside courts.