Alexandria is a city where if colonial history seems to live in half the houses, recent memory rarely survives. Restoration has put its stamp on Old Town, and any visitor can wander through the favorite haunts of George Washington or Robert E. Lee. But its residents seem to come and go every few years.

Not so in Beverly Hills. Straddling the city's North Ridge, Beverly Hills displays some of the opulence but none of the extravagence of its West Coast namesake. Its only gaudy display is the informal azalea festival that each spring transforms the leafy neighborhood into a blazing garden show. It is a neighborhood in which most residents seem to enter a friendly, unofficial competition to outdazzle each other with more and more abundant displays of azaleas.

Continuity is the key to the community.

"I've lived on this hill since I was 10 years old," said Joe Blackwell, 73, an elder of the area, which is bounded on the north by W. Glebe Road, the west by Quaker Lane, the south by Braddock Road and the east by Russell Road.

Blackwell himself has planted more than 300 varieties of azaleas around his stone Cape Cod home at 306 Beverly Dr.

"Cameron Mills Road was a cow path when I was a child," said Blackwell. "It used to be all the government folks moved out here. That's changed a little, but the place has always been peaceful. I still know my neighbors."

It is not unusual to find two or even three generations of the same family living in Beverly Hills, part of a slightly larger neighborhood called North Ridge. Beverly Hills' residents are nothing if not loyal. Churches and schools form the backbone of the neighborhood, and after a decade of demographic quietude, civic leaders are pleased to see a surfeit of strollers rolling through Monticello Park most mornings.

When asked how best to describe this community of big houses and perfect lawns, one Alexandria politician put his hands on his hips and spoke three simple syllables: "La Di Da."

The figures back him up. According to 1980 Census statistics, the latest that have been compiled for the North Ridge area of Alexandria, the area -- with houses costing an average of $150,000 and ranging quite a bit higher -- is far beyond the means of today's average wage earner. In 1979, the median income for families in the neighborhood was $36,284; city planners say that today the median income is significantly higher.

The census showed that, of North Ridge's 7,000 residents (there are now about 108,000 in the entire city), the vast majority -- more than 95 percent -- are white. Among the many national trends of the past decade that Beverly Hills largely has resisted is the big increase in the number of households; the fancy colonial and Cape Cod houses and large price tags make this an unusual place for a single person to choose to live. In 1980, less than 25 percent of the area's households consisted of single people. About 80 percent of the residents owned their own homes.

In a city that is one of the District's most urban neighbors and one that increasingly is marked by new tongues and changing traditions, the overwhelming majority of Beverly Hills' residents are married people with children. It is, on the whole, a politcally conservative Republican enclave in a city that has been predominantly Democratic.

"I have lived in Beverly Hills for years," said Robert L. Calhoun, a Republican member of the City Council. "And my house built around 1950 is one of the newest on my street. It's a very stable place. It has few of the tensions that came with the rapid change in so many other parts of the city. In the '60s, all of a sudden there were such huge transformations of other neighborhoods. Great gaps developed. Beverly Hills basically avoided all that."

But even for Alexandria, where it is never easy to lay claim to history, the North Ridge has a rich heritage. Although it has been an official part of the city only since 1929, the neighborhood has played its role in the affairs of the region.

John Alexander bought the place and a few more acres to go with it from an English ship captain in 1669. The price was a pound of tobacco per acre; 6,000 pounds of tobacco changed hands for 6,000 acres. The original city of Alexandria was built on a portion of this land and named for Alexander.

During the Civil War, as many as 10,000 Union troops occupied Alexandria to help protect Washington, and many of them were stationed on the North Ridge. One house on North Overlook Drive was said to be a major Civil War hospital where Walt Whitman served as a nurse.

Even today it is not at all uncommon for children rooting around in their back yards to find what turn out to be shells from the Civil War.

Although it bordered on Washington, a rural life style characterized the area until the turn of the century, when, gradually, the parcels of old farms began to be divided into lots for houses.

Beverly Hills, like much of the northern Alexandria area, began to take shape at the end of the 1920s.

"It started in the '30s, with young people moving out of the inner city," said Rev. William E. Basom, who first came to the neighborhood in 1937 to start the Beverly Hills United Methodist Church, which has been one of the foundations of the community's activities. "The adults would get together in the winter to set up bonfires on the hilltop. It was really like an isolated little town."

In the 1930s, the houses many people still occupy today cost from $5,000 to $8,500, and most of the new families worked for the government. Now their homes are worth $150,000 or more.

World War II and the emergence of the Pentagon as one of the region's major employers changed Beverly Hills considerably. It became a favorite of service personnel, which meant that it was subject to the rapid turnover that comes with a military life.

The neighborhood has played home to its share of the famous folk who govern the nation. For a while, Richard Nixon lived just next door in Parkfairfax. Former Virginia governor Charles S. Robb lived there for a short time, as have dozens of other elected and appointed officials.

In recent years, as more residents who live in the neighborhood work in Alexandria, there has been a return to the cohesiveness that originally set the neighborhood apart.

Every year, children at George Mason Elementary School -- along with those at McArthur and Charles Barrett, the three public schools that serve children in the community -- score higher on standardized tests than anywhere else in the city.

"Parents here are very involved in what goes on at the school, and they always have been," said Rosalind Bovey, a past president of the North Ridge Civic Association who a few years ago put out an informal history of the area called "North Ridge Lore."

"This is not a place where it is difficult to find people for the PTA," she said.

Most residents use cars to get around, but the Metro subway station at Braddock Road is easily accessible by DASH, the city bus system. Metro buses also serve the neighborhood. While some residents shop in Old Town, most turn to the malls: Landmark is the nearest and most convenient, but Fairfax's Springfield Mall and Tysons Corner also attract Beverly Hills shoppers.

"You'll never get me off this hill, I love it," said Blackwell, who in addition to being able to recite the history of the area, is the unofficial guardian of the Beverly Hills azaleas. "This is a beautiful, graceful place to live, and I've always felt lucky to be here."