Friends and cab drivers have a hard time finding Donna St. John's tiny, century-old, two-story house on Snow's Court in Foggy Bottom. It isn't on the map.

There is no front yard and no parking space, and yet St. John is delighted with her slice of uncelebrated history, hidden behind the row houses and apartment buildings near 25th and K streets NW.

St. John's home is one of Washington's few surviving alley dwellings. Built after the Civil War in interior courtyards of the larger city blocks, about 3,000 of the tiny houses once dotted the city. They had no bathrooms or running water, and became such blighted slums that Congress outlawed them in the 1930s. Now barely 100 remain.

These formerly unloved houses, which rented for about $9 a month in 1910, now sell for more than $100,000: Once slums, they are now luxury housing.

The alley dwellings were first occupied by European immigrants or Southern blacks who packed large families into each floor of the two-story houses. By today's standards, the houses seem only large enough for two people. So small is St. John's 500-square-foot house on Snow's Alley that she says she had to buy smaller furniture and is forced to keep her out-of-season clothing in the trunk of her car.

The alley dwellings are a distinct breed, not to be confused with carriage houses or converted garages. The dwellings, unlike other such structures, were built on their own lots.

The original inhabitants of the alley dwellings, which were built in Georgetown, Foggy Bottom and Shaw and on Capitol Hill, worked at the local breweries or bakeries or as domestics, and tried to survive in an expensive city without much help from the local government. There was no trash collection in the alleys and police did not patrol there. Social reformers who ventured into the alleys reported tightly knit communities that did not welcome outsiders.

The alleys took on colorful names, many of which survive on the city's old plat maps even though the dwellings are long gone: Goat Alley, Tin Cup Alley, Temperance Court, Chow Alley, Butts Alley, Porksteak Alley, Hogshead Alley, Cabbage Alley, Odd Fellow's Alley, London Court and O'Brien's Alley, among others.

Snow's Court is believed to be named for C.A. Snow, the publisher of the once-popular National Intelligencer newspaper, who built four houses and a greenhouse at that location before the Civil War. Sometime around 1880, about 30 little brick houses were built in the alley, making it one of the larger inhabited alleys with a population of over 200.

Today the residents of Snow's Court are mostly professional or retired people who take pride in the attractive warren of 23 neatly kept, multicolored row houses with tiny front steps, miniature flower boxes and pathways lined with zinnias and begonias.

"This place is quiet, more quiet than the apartment I had half a block away," says St. John, 36, who walks to work at the Veterans Administration, where she writes and edits a newsletter on Agent Orange. "When I sit in my back yard, I don't feel as though I am even in the city."

The sense of isolation in the midst of the city, so charming now, was considered a real danger by the social reformers of the early 1900s, who deplored the condition of the alleys and the fact that officials paid so little attention to them.

Books and newspaper articles of the time called them "civic plague spots." Eleanor Roosevelt, wife of the president, and various congressmen toured the alleys to see conditions firsthand. Congress passed legislation in 1919 and again in 1934 to "provide for the discontinuance of the use as dwellings of buildings situated in alleys and to eliminate the hidden communities in inhabited alleys of the District of Columbia."

By the time the Alley Dwelling Authority was formed in 1935 to implement the wishes of Congress, the population of the alleys had dropped and some of the buildings had been converted to garages or warehouses.

Eight years later, in the middle of World War II, the authority had demolished a great number of the alley dwellings, erected public housing as well as temporary war housing, and changed its name to the National Capital Housing Authority. The deadline for the final "discontinuance" of alley dwellings was extended from 1944 to 1955.

After World War II, there was a new interest in housing in downtown areas once again. Developers and individuals bought and spruced up Bell's Court (now called Pomander Walk) and Cherry Hill Lane near the Georgetown waterfront. Library, Miller, Brown and Terrace courts on Capitol Hill, among others, were transformed into charming and expensive lanes. In Foggy Bottom, Snow's Court and Hughes Court (now Hughes Mews) were rehabilitated, along with the larger houses bordering the State Department and George Washington University.

The status of these refurbished alley dwellings was precarious: Despite the addition of plumbing and other refinements, the congressional mandate to end all alley dwelling by 1955 still stood.

Bob Lyle, now the curator of the Georgetownia collection at the Georgetown Library and a homeowner on Cherry Hill Lane, remembers the spirited debate between the city commissioners, who wanted to raze the houses, and the new alley dwellers, who wanted to keep them, when they met in September 1953.

Lyle says now: "I was confident we would win. The house was $7,000 and it was all I could afford in 1952. When I bought it there were no stairs in it and the back yard was used as a junkyard for scrap metal and newspaper. But we fixed it up. And it was quiet back then. A lot quieter than it is now."

The new alley dwellers won their exemption, and Lyle and his new neighbors held a block party to celebrate on May 14, 1955.

About the same time, Benita Belden was the first person to move into the newly renovated Hughes Court, located between 25th, 26th, I and K streets NW. She liked it so well that she bought two more of the houses and has committed every unoccupied patch of ground to flowers and tomato plants.

"When we moved in, all of this was a vacant lot," she said, waving her hand in the direction of several tall apartment buildings that face 25th Street. "And this was all a mud puddle in front of the houses. And over there were all Negro shacks near 26th Street. I used to shoot craps with the little boys and they always beat me. We didn't ever lock our doors. We all lived here together, and we talked and helped each other out."

Belden, 71, said a neighbor named Charles Rogers petitioned the government to change the name of the court to Hughes Mews.

"That was 15 years ago," she said. "I remember he tried it once and failed, and then he got it the second time around. And then he moved out, leaving us with that name, Hughes Mews."

Many of today's alley residents became interested in their unusual homes after moving in. John Vlach, 35, now a George Washington University anthropologist specializing in Afro-American architecture, is an exception. He had reviewed the book "Alley Life in Washington," written by James Borchert, before arriving in Washington in 1981.

"I thought the alley houses would be out of my price range, that gentrification would have set in," he said from his home on Terrace Court NE, directly behind the Supreme Court.

"By a stroke of good luck, I plugged into an academic and Smithsonian pipeline and this house was offered to me at a reasonable rent. As soon as I came here, I knew this house was the best of everything I had seen."

"We are a little row of buildings set under the nose of the monuments in our own hidden world," said Vlach. "In a sense, this house is an element of an earlier folk culture now gone. And we are the new folk culture. We are upscale alley dwellers."