A few miles past the new, modern homes and buildings of Columbia, you turn off Route 29 and descend a narrow winding road into the 19th century. Granite houses built shoulder-to-shoulder, on one side of the road dug into the steep hill, on the other perched perilously over the cliff, their doors open directly onto a single-file sidewalk. There are no front yards in Ellicott City.

Jammed into the valley - gorge actually - of the Patapsco River, Ellicott City has been the victim of several major floods, including a devastating one during Hurricane Agnes in 1972. But the town has recouped its losses, for the perserverance and industriousness of the townspeople is no different now than in 1772 when three Quaker brothers - Joseph, John and Andrew Ellicott - left their home in Bucks, County, Pa., to build a flour mill on the river and settle Ellicott Mills.

From granite quarried nearby, the Ellicotts also built a Quaker meeting house, stores and houses. When the town received a city charter in 1867, the name was changed from Ellicott Mills to Ellicott City, but there is currently a movement among a few nostalgia buffs to change the name back to the original. This seems a remote possibility, however, since the town is the county seat of Howard County and countless documents would be affected. And there's dispute over what the original was - Ellicott's Mills, Ellicotts' Mills and Ellicotts Mills all can be documented.

The narrow streets and granite buildings which have survived since the early 1800s kept the town from changing much over the years. This "living museum," as residents describe the historic area, is mostly confined to Main Street and Tongue Row. Built for mill workers in the early 1800s and owned by a Mrs. Tongue, the townhouses on Tonge Row, like the larger buildings on Main Street, now house mostly specialty shops and studios.

One Ellicott City shopping trick is to wander in the back rooms and up the stairs. Some of the best finds - antique furniture, jewelry, glad rags, hand-dipped candles, pottery, clocks and photographs - can be found on third-floor rooms or tiny alcoves behind the main stores. It's possible to find an old tin coffee mill for $29 or a 19th century cast-iron room stove patented in 1877 for $125.

Usually the owner is in the store. If he or she isn't busy, you've found a ready source of local history and gossip. And some shopkeepers have been known to barter away an item rather than sell it. If you're really lucky (and persuasive) you might get a free tour of a renovated apartment above a store. Many of the buildings were originally built with a shop downstairs and living quarters upstairs. Several owners are reinstituting this arrangement. The two private apartments to which I was privy were real showcases of handiwork and decorating talent. One was located in the upper portion of an old mill, the other above a storefront on Main Street.Absolutely charming.

In 1831, the B & O Railroad established its first 13-mile stretch of track between its newly built terminal in Ellicott Mills and the Mount Clare Station in Baltimore. (The track was used for the famous race between the Tom Thumb locomotive and a horsedrawn train.)

At the foot of Main Street, this first American railroad terminal is now a B & O Railroad Station Museum, with restored waiting rooms, offices, servicing areas and an archeological excavation of an old-fashioned turntable. Volunteer tour guides enthusiastically recreate the excitement generated by the advent of the railroad in this country.

The best features of the museum include an extensive model train replica of the first 13 miles, restored rooms that once functioned as segregated waiting areas for men and women, and an aura of history which pervades the entire structure. Open Saturdays and Sundays 11 a.m. to 4 p.m., admission is $1 for adults, 50 cents for children.

All the walking and bargain hunting is bound to make visitors hungry. There are several quite different restaurants situated in historic Ellicott City.

The most homey is Pica-Deli Cafe at 8089 Main Street. Local townspeople congregate here to swap daily news while sampling homemade soups and hot sandwiches. Seating is limited so much of this delicatessen's business is carryout. However, it's a treat to sit and eat here, for the walls are decorated with a monthly art exhibit by local artists. Pica-Deli closes at 6 p.m. on Saturdays and Sundays.

Cacao Lane Restaurant, 8066 Main Street, offers a classic New York pub atmosphere with storefront window seating, brick floors and hanging plants. To enter Cacao Lane, you have to go through a wrought iron gate and granite tunnel, then turn right for the restaurant, left for the bar (a popular local after-dark gathering place). Luncheon items include quiches, salads and hamburgers. Dinner is strictly Continental with entrees like Chicken Cubano, Scampi and Veal Orleans. Reservations are necessary on Friday and Saturday.

Chez Fernand, 8141 Main Street, boasts devoted and personal service and prices in keeping. French-style cuisine from escargots and vichyssoise to Dover Sole Almondine ($9.95), Steak Diane ($9.25) and Chateaubriand ($20.95 for two). The finale can be Camembert and fruit, crepes suzettes or chocolate mousse and espresso. Reservations suggested, especially Saturday night.

One word of caution - wear comfortable shoes on any jaunt to Ellicott City. Most of the stairs are winding. And apparently they didn't believe in railings back when.