THERE is no sign erected or banner unfurled.

Coldspring, the planned community in Northwest Baltimore once heralded as the salvation of a declining city, is turning 25 -- with scant fanfare.

Del. Samuel I. "Sandy" Rosenberg, Coldspring's longest continuous resident, is holding a private party next month to mark the occasion of his move there on Christmas weekend in 1977, but says he knows of no public events to commemorate the community's anniversary.

Neither does Zoltan Annau, a past president of the Coldspring Community Association and an 18-year resident.

"We're a very small community. We can't afford to put on any kind of big celebration," Annau said.

Indeed, Census 2000 data put Coldspring's population at 880 and the number of housing units at just more than 500.

Of the latter number, half are Coldspring's original futuristic "deck houses" -- townhouse condos linked by plazas and walkways, with parking spaces underneath -- designed by internationally renowned architect Moshe Safdie and built in the late 1970s and early 1980s.

The remainder are in two senior citizen buildings and The Woodlands, a small complex of suburban-style detached and semidetached houses -- all built later among the community's winding roads and forested hills.

Coldspring -- bounded by Cylburn Arboretum on the north, the Jones Falls Expressway on the east, Coldspring Lane on the south and Greenspring Avenue on the west -- is also home to the private Waldorf School.

That's a far cry from the ambitious plan for the community. Hatched in the late 1960s and early 1970s, the plan called for a "New Town" of about 3,800 units on both sides of Coldspring Lane with more than 12,000 residents, offices, stores and a conference center.

It was hailed as an antidote to the exodus of residents from the city that was just beginning.

"Coldspring has the potential of becoming for residential Baltimore what Charles Center was for downtown Baltimore: a dramatic catalyst and inspiration for the development of attractive and reasonably priced urban housing," this newspaper rhapsodized in 1971.

The community attracted an eclectic mix of residents -- college professors, newspaper reporters, public officials.

But obituaries for the grand scheme began to be written not long after the boxes were unpacked. The economy tanked. Interest rates spiked. Federal aid that fueled the project dried up. A lawsuit over structural flaws drew unwelcome attention. A design that was intriguing to some was downright quirky to others.

Today, Coldspring is a little like a child prodigy who grows up not to be a genius but a bright young adult.

Although far smaller than originally envisioned, Coldspring was one of the few city neighborhoods to gain population in the last decade, thanks largely to the opening in the mid-1990s of The Woodlands. Homeownership is substantially above the citywide average; vacancies, significantly below it.

Rosenberg, a Democrat who has represented Northwest Baltimore for 20 years, said he was initially drawn to Coldspring by the idea of a "self-contained community" within the city; he stayed because "I love my unit."

The bucolic setting that keeps Coldspring out of sight and out of mind of the rest of the city is part of its appeal.

Jane Houck, president of the community association, takes a long walk every morning at 6. "I wish more of Baltimore could recognize what a wonderful place it is to live," she said.

Looking back, it seems the potential effect of Coldspring was overstated from the start.

The past quarter-century has taught us that people didn't leave the city because of a lack of innovative housing; they left because of increasing crime and declining schools.

New housing has a role in attracting new residents, but it seems to work best when it is integrated into existing neighborhoods -- such as Whetstone Point in Locust Point, or Spicer's Run in Bolton Hill.

The future of the city lies not so much in the creation of new communities as in the reconstruction of existing ones.

Interestingly, at about the time city leaders were planning Coldspring, they were trying unsuccessfully to push for an expressway that would have gutted many waterfront neighborhoods that now are creating hopes for a citywide resurgence.

There seems another lesson in the history of Coldspring as well, worth pondering as the city pushes ahead with such large-scale initiatives as the west-side renaissance and east-side biotech park.

Anyone who cares about Baltimore's future can only hope those projects meet, or even exceed, the city's expectations.

But as Coldspring has taught us, despite the best minds and best intentions, nothing is a foregone conclusion.