In an attempt to lure the growing number of families raising their children in New York City, several new residential developments are catering to preteenagers with age-appropriate amenities.

Whereas children growing up in the suburbs may spend their summers riding their bicycles around the block — or playing ball in the front yard — city youngsters living in certain buildings can participate in “tween” exercise classes, play virtual reality games in elaborate recreation rooms, or stargaze from a rooftop observatory.

The 450-unit One Brooklyn Bridge Park in Brooklyn Heights, for example, features an indoor virtual golf simulator, an outdoor putting green, as well as a game room, art studio, and soundproof room to practice music.

“We know that even though the adults may be writing the checks, they want to move to a place where their children are happy,” a senior vice president for Stribling & Associates who is the sales director for the One Brooklyn Bridge Park, Jeffrey Stockwell, said.

The soon-to-open Solaria in Riverdale took a different tack to garner the attention of families with preteenage children. The 65-unit building partnered with the Amateur Astronomer’s Association of New York to offer stargazing sessions at its rooftop observatory.

“It’s got to be a thrill to be able to see the solar system,” a Solaria developer, Joseph Korff, said, noting that he expects the observatory will have a particular cachet with the middle-school set.

Meanwhile, a condominium rising on East 85th Street, the Lucida, is partnering with La Palestra Fitness, Wellness and Spa Center to create an exercise program tailored to the building’s “tween” residents. The president and program director of La Palestra, Pasquale Manocchia, said these classes would help supplement schools’ physical education programs, teaching the importance of living an active lifestyle from an early age.

The 65-unit building is scheduled to open in early 2009.

Across town, the Element condominium — with 198 apartments that will be ready for occupancy in November — will feature an on-site ballet academy, five dance studios, and a performance space. These amenities are “every mother’s dream come true,” a developer of the West 59th Street project, Jane Gol, said.

“The concept of having it all there is really appropriate for this tween group,” Ms. Gol, a managing partner at Continental Ventures Realty and a developer of the building, said. “Parents can let children develop and be free, and yet know where they are.”