On the cobblestone streets of Old Town Alexandria, Christmas arrives wrapped in swirling tartan. This Saturday, brigades of bagpipers pipe in the season with their ninth annual Scottish Christmas Walk in honor of the founders, a day when historic homes -- even some private ones -- are all decked out and open for visitors.

Any time of year, a walking tour of Old Town can be just like window shopping -- picking up fragments of history and mystery, and sometimes, bumping into a ghost. Though to some it's just another colonial town, residents tend to take their history seriously, with plaques on their housefronts and markers on their historic buildings.

After all, Alexandria was the closest thing to a hometown George Washington had. And one of its favorite sons, Robert E. Lee, went back there just to see the snowballs in bloom by the house he lived in on Oronoco Street.

Local folklore has it that the cobblestone paving Ramsay Alley, or Captain's Row a block away, provided ballast on Hessian ships during the Revolution. As prisoners of war, Hessian soldiers pounded the cobblestones into the streets.

But who can be sure? As Ramsay Alley resident Horace Day says, "People as a rule especially with Virginia history, are loath to investigate too much. It's an oral tradition very seldom confirmed by archeological or historical knowledge." He theorizes that northerners who move to Alexandria are more likely to plaque their houses and dig into the history. "The southerners," he says, shrugging, "have always been here."

Up on South Fairfax, in the Stabler-Leadbeater Apothecary Shop, Donald Slaugh sits in the director's desk, sort of wedged between past and present. His half of the shop sells antiques. The other half appears the way it did in 1792, and, until it closed in 1933, it was considered America's second-longest-running drug store. Still standing sentinel in a window is a glass globe full of red liquid, which, it's believe, signalled travelers not to stop because there was a disease in the town.

Now the apothecary shop is a museum. "It's run by a bunch of nice little old ladies in sneakers," says Slaugh. And it isn't easy overseeing it: "In March come the senior citizens. They pick up everything and drop everything. Then the Boy Scouts -- Lord preserve us from them."

There are crank phonecalls: "Is my prescription ready?" Click.

Since a few real drugstores are still named apothecaries, some people dial the old shop by mistake. "They'll phone up," says Slaugh, "and ask for Dr. Stabler. Whereupon I tell them he is deceased, whereupon they express their regret -- whereupon I tell them he died January 1831, whereupon they hang up."

The old apothecary shop hasn't been the same without the good doctor; even Slaugh realizes that. "Every once in a while upstairs there use to be this thump and then something dragging across the floor. I thought we had birds up there. But I went up, and there was nothing -- not a mark in the dust. Then another time I'm sitting here and all of a sudden the contribution jar was jangling around. I said, "Goddammit, knock it off!' And he did. Somebody came in and said, 'You put out the wrong vibes.' Well now, doggonnit, I miss him. What am I supposed to do, go in and apologize?"

Wherever you walk in Alexandria, people have their favorite villains and folktales. At Carlyle House, the villain is one James Green, who around 1850 built a hotel smack in front of the 1752 Georgian mansion. It wasn't until 1974 that the hotel was demolished, revealing Carlyle House to modern Alexandria.

In Gadsby's Tavern, the stories you hear sometimes depend on which docent leads the tour. As curator Gretchen Sorin says, "Some people in town get very emotional about the old stories. If somebody comes here and hears one story they call and complain. They want to hear another story. So we tell people that these stories are related to the museum, but we want to be accurate."

There's the one about the Female Stranger, who's buried in St. Paul's Episcopal church cemetery. The grave marker says: "To the Memory of a FEMALE STRANGER . . . This stone is placed by her disconsolate husband in whose arms she sighed out her latest breath . . ." and ends in a few lines the disconsolate one lifted from an elegy by Alexander Pope.

"We know," says Sorin, "that in 1816 a young woman very ill came to the tavern. She came with a man we presume to be her husband, and that everything was done for her to save her life. She died in the tavern.

"For some reason they wanted to keep her identity a secret, we presume because her husband was wanted for some crime in England."

Local tradition says the Female Stranger's husband went into the Maryland woods and became a hermit. For a long time he'd return and cry over her grave. They called him Cabin John.

Her memorial is a long slab raised on pedestals, and I asked someone who sells headstones what to call this unusual table shape from the early 1800s. He didn't know its name, but when I off-handedly mentioned that her husband (if he was her husband) never paid for it, he said, "Well, that's par for the course. It's the really elaborate ones we have the most trouble collecting on."

It was hard to resist playing Cabin John and making the pilgrimage myself. Beside the Female Stranger's grave, the wind of the night before had carried and dropped a small homemade creche. Its gable was painted white, with red ribbon glued to the roof's edge, and turned face down, pointed to her memorial like an arrow. The person who made the creche had tacked tiny plastic poinsettias and greens to it, and as I turned it over, a little plastic Gabriel fell away.

On a walking tour you can't help but wonder why things are built the way they are. The flounder house is a curious architectural fish: there are no windows on its flat-faced side and it looks like half a house. No one knows for sure whether it was slapped up to meet early building codes that gave 1750s residents two years to develop the property, or it just happened to suit the narrow city lots. A good example is the flounder at 316 South Royal Street, behind the Presbyterian Meeting House. It's the church office.

Then there are tiny alley houses, which people like to think were built by one owner as a "spite house," to lay chaim to the alley, to spite the person who lived on the other side. One alley house, 205 King Street, is now a shop that sells clogs. Another, 523 Queen Street, is a private home, but more like a dollhouse, a little over 7 feet wide.

Like most of the buildings in Old Town, these alley houses were named in a survey of early buildings as being at least 100 years old. The provenance of the old buildings has been catalogued in a book, "Historic Alexandria, Va., Street by Street," by Ethelyn Cox.

When the book came out, says Richard Bierce, historic resources coordinator for Alexandria, "it surprised a lot of people, challenged a lot of popular myths.

"A common problem around here is that everybody wants a piece of the 18th century," says Bierce. "Even though the facts are all but irrefutable that a particular house or part of town was not even developed until mid-19th century, there is a tendency to believe it was developed a lot earlier. But you can't please everybody."

Local traditions tend to accumulate, and sometimes there's truth to them. "I'd always thought that General Braddock didn't stay in the Carlyle House," says historian Cox, "because it was quite hot. Tradition turned out to be right, when they turned up letters overseas. Until Carlyle's letters showed up a few years ago, I thought that was just one of those nice stories."

She doesn't put much credence in the one about the cobblestone streets: "I have the feeling that the Hessian prisoners of war never paved them. All the newspapers indicated they didn't pave anything 'til after the Revolution. And there were advertisements in the early newspapers describing the kinds of stones Alexandria wanted," says Cox. "I didn't belabor it in my book. As for the story, if people like it, that's fine. People always like stories better than the truth." SATURDAY'S WALK The bagpipers start at 10 at Scotland House in the 600 block of South Washington Street and head for City Hall (King and Fairfax), for a massed-bands concert and ceremony at 10:30. Other activities include boutiques and hot punch heartside at Alexandria Community Y (602 Cameron), a collectors' corner at Saint Paul's Church (228 South Pitt), a children's program at the Elks' Club (308 Prince) and house tours. For details, see the Y's information center, at City Hall from 10 to 3. HISTORIC STOP-OFFS 1 -- MARKET SQUARE This brick-paved plaza with a fountain fronts City Hall. Here, on July 13 and 14, 1749, half-acre lots were auctioned off for about $80 apiece in the newly founded town of Alexandria. 2 -- RAMSAY HOUSE (221 King St.) The oldest house in town, believed to have been built in 1724 in a Scottish settlement 30 miles south. Town trustee and merchant William Ramsay may have floated part of the house up the Potomac on a barge. Through the raging fortunes that saw the town shift from prosperous seaport to occupied city to bedroom community, the clapboard house was to serve, at various times, as tavern, brothel and cigar factory. It's now Alexandria Tourist Council, and, for the tourist-on-foot, offers a garden to rest in, brochures on what to see or where to spend money, and restrooms. (Open daily, 10 to 5. Call 549-0205.) 3 -- CARLYLE HOUSE (100 block of North Fairfax) In April, 1755, the British Commander, General Braddock, met here with five royal governors to hash out how to get the colonists to finance his campaign against the French and Indians. This led to the Stamp Act. Carlyle wrote to his brother in Scotland: "The general & his aid de camps, secretary & servants lodged with me, he took everything he wanted, abused my home, & furniture, & made me little or no satisfaction." (Hours: Monday through Saturday, 10 to 5, Sunday, noon to 5. Admission $1, children, 50 cents.) 4 -- BANK OF ALEXANDRIA (133 N. Fairfax St.) By Act of the Virginia Assembly in 1792, the Bank of Alexandria became the state's first bank. George Washington opened an account there. John Carlyle's daughter Sarah was married to the bank's second president, William Herbert, whose name continues in Alexandria banking. It was completed in 1807 and is now being restored. 5 -- GADSBY'S TAVERN (132 N. Royal St.) The underground ice house on the corner was dug out by 1805, when John Gadsby sold ice from the river for eight cents a pound. At the sign of the bunch of grapes, Gadsby's Tavern is really two buildings. The smaller dates from 1770, when it was Wise's Fountain Tavern; it's now a museum. The larger one on the corner was the City Hotel when it was built in 1792 and housed the ballroom where Washington's Birthday balls were held. In 1917, the Metropolitan Museum of Art bought its front doorway and the ballroom. It lent the doorway back for the Bicentennial, but the ballroom you see on the tour is just a good copy. Downstairs is a restaurant. Though John Gadsby only leased the City Tavern and Hotel, and never owned them, he's the most famous boniface. He greeted guests there for 12 years, until 1808. He was later to open a hotel in Washington, reside in Decatur House and come to his final rest in Congressional Cemetery. (Hours: Tuesday through Saturday, 10 to 5, Sunday, noon to 5. Admission $1; children, 50 cents.) 6 -- ARCHEOLOGY RESEARCH CENTER (Torpedo Factory, Union Street) A visit to the archeology center is by appointment only, for a slide show and tour, to see how they clean, reconstruct and date artifacts found in wells and privies of early Alexandria. Call 750-6200 weekdays between 9 and 4 to make reservations. (Of the four structures that make up the Torpedo Factory, two were built during World War I and two in World War II. The Torpedo Factory Art Center, King and Union, is open daily from 10 to 5.) 7 -- FITZGERALD'S WAREHOUSE (6 King St.) Now the Seaport Inn, the warehouse belonged to Col. John Fitzgerald, a merchant who was friend and aide de camp to Washington. He served as mayor of Alexandria, and later, collector of the port. In those days, a loft on the fourth floor was a place for drying sails. 8 -- STABLER-LEADBEATER APOTHECARY SHOP (105-7 S. Fairfax St.) Labels on the porcelain drawer pulls -- myrrh, rhum, pigmentia, enema -- make you grateful you weren't around to get sick in 1792 when this drugstore first opened. Washington picked up his mail here and is said to still owe money here. When Daniel Webster and John Calhoun engaged in philosophical debate, Stabler opened the doors to entertain the passersby. (Hours: 10 to 4:30. Closed Sundays.) 9 -- GENTRY ROW, CAPTAIN'S ROW (the 200 and 100 blocks of Prince Street) Some lovely old townhouses, now private homes. Early on, sea Captain John Harper owned property on Captain's Row. The street is cobblestone on this block. According to Ethelyn Cox, the appellation "Gentry Row" was coined in the 1950s to described the residents. 10 -- ATHENAEUM (201 Prince St.) Originally the Old Dominion Bank, built in the 1850s, this Greek revival structure is now the gallery of the Northern Virginia Fine Arts Association. (Hours: Tuesday through Saturday, 10 to 4, Sunday, 1 to 4.) 11 -- DR. WILLIAM BROWN'S HOUSE (212 S. Fairfax) Private residence. Late 1700s, it's brick under all that clapboard. Washington appointed Brown physician-general and director of hospitals of the Continental Army. 12 -- DR. JAMES CRAIK'S HOUSE (210 Duke St.) Private residence. With Washington, Craik kept the death watch for General Braddock when defeated in the French and Indian War. Years later, in December, 1799, Craik would be at Washington's bedside when he died. 13 -- OLD PRESBYTERIAN MEETING HOUSE (321 S. Fairfax St.) Lighting struck the steeple of the late-18th century building in 1835 and, according to church records, "A period of 2 hours had not elapsed from the commencement of the conflagration before the whole edifice, except the walls, were involved in one shapeless mass of smoking ruins.' "I guess," says the current minister, William Sengel, "the purists, particularly among the architects, have a little trouble identifying." But old headstones in the cemetery behind the church still mark the graves of John Carlyle, James Craik, Col. Dennis Ramsay (son of William, born in Ramsay house) and an unknown Revolutionary War soldier. Behind it, the flounder house, now the church office, was built in 1787. (The church is open 9 to 4:30.) 14 -- LAFAYETTE HOUSE (301 St. Asaph) Private residence. Lafayette slept here, 1824. According to local tradition, he came out to speak to a crowd of welcoming Alexandrians, but was escorted around the corner to Dulany House (601 Duke St.) where the front stoop is higher. 15 -- THE LYCEUM (201 S. Washington). Greek revival with Doric columns, the Lyceum was built in 1839, by, among others, Elias Harrison, a minister at the Presbyterian Meeting House, and Benjamin Hallowell, an educator who tutored Robert E. Lee in math. The Lyceum was for lectures "on literary, scientific and historical subjects, to be followed by debate; political and religious subjects barred." During the Civil War, Union troops used it as a hospital. It's now the Bicentennial Center. (open daily, 9 to 5.) (Note the Confederate soldier statue on the median strip outside of Washington Street.) 16 -- FRIENDSHIP VETERANS FIRE ENGINE CO. (107 S. Alfred St.) Organized in 1774, the company claims Washington as a member. The hand-pump fire engine he donated gleams on display there, along with early helmets, capes and leather water buckets. Open this Saturday only for the Christmas Walk. Hours: 11 to 3. Admission $1; children free. 17 -- CHRIST CHURCH (Cameron and Columbus) The Georgian architecture is noteworthy. Washington went to church here and sat in pew 60 (marked by a silver plaque). Robert E. Lee's pew was No. 46. William Ramsay, the town trustee who lived in Ramsay House, is buried in the churchyard. (Hours: 9 to 4, except Sunday, 2 to 5.) 18 -- "GEORGE WASHINGTON TOWNHOUSE" (508 Cameron St.) Private residence. A replica, built on the same site as the original. 19 -- The lloyd HOUSE (220 N. Washington) Built in 1797 by John Wise, it's the repository for Alexandria Library's rare books, records and documents. (Hours: 9 to 5, closed Sundays.) 20 -- LEE-FENDALL HOUSE (429 N. Washington) Philip Fendall built the house on a lot he bought from his stepson-in-law, Lighthorse Harry Lee. Fendall holds the distinction of having married three Lee ladies in succession. At one time or another, 30 Lees lived here between 1785 and 1903. It's now a shrine to the Revolution's Lighthorse Harry, who didn't live here. (Hours: Tuesday through Saturday, 10:15 to 4:30, Sunday, noon to 4:30. Admission, $1, children 75 cents.) 21 -- LEE BOYHOOD HOME (607 Oronoco St.) Lighthorse Harry Lee lived here, and so did his son, Robert E. Lee. (Hours: Monday through Saturday, 10 to 4, Sunday, noon to 4. Admission, $1.50, children 75 cents.) 22 -- GW MASONIC NATIONAL MEMORIAL King Street and Russell Road) Because he was a charter member, much Washington memorabilia is on view, including the chamber clock that was stopped when he died. For a commanding view of Alexandria, the Potomac and points beyond, tour the tower. From the wide ground floor, the elevator shafts slant inward at a 7 1/2 degree angle, up 330 feet to the top. (Open daily, 9 to 5.)