Directions: Take I-95 to Baltimore's Inner Harbor. Right on Pratt Street until South Broadway, right on South Broadway until Lancaster.

Hours: 11:30 a.m. to 11 p.m., Sunday through Thursday, 11:30 a.m. to midnight, Friday and Saturday.

Atmosphere: Warm, charming, simple. Families welcome.

Price: Steamed mussels: $4.50. Other dishes: $5 to $8.

Reservations: Helpful. May still have to wait.

Credit cards: None. Personal checks accepted.

Special facilities: Parking in municipal area on South Broadway. Handicapped would have some difficulty negotiating entrance and stairs.

Every other car in Baltimore, it seems, displays a bumper sticker that reads "Eat Bertha's Mussels." And almost everyone does.

We did.

They are delicious: steaming hot, large, sweet black-shelled mollusks, barnacles and seaweed still clinging to some, piled onto platters that catch the butter and garlic or wine and tomato sauce in which they are cooked.

A fine meal in itself for about $4.50 (which includes 18 to 24 mussels plus excellent crusty French bread and good butter), or $5 if you splurge on one of Bertha's nice leafy salads with unusual homemade dressings of either curry and lime or blue cheese and cream.

Mussels are what made Bertha's famous, but there's more. The mostly seafood menu has almost none of the standard wharfstyle dishes you usually find. No fried shrimp nor fried scallops, no mariner's platter at Bertha's. Too mundane.

Instead, there are Bertha's shrimp, broiled in a strong and delicious lemon-garlic sauce thick with sliced scallions, served over French bread that sops up the sauce. Or there's shrimp Maurice, broiled with honey, lemon, garlic, butter and sherry, another innovative dish. One complaint: Bertha's give you only a bare half-dozen small shrimp in these dishes.

There are variations on paella, and fresh fish dishes, such as flounder stuffed with crabmeat, daily.

The only item we could find that carried over from standard seafood menus was the crabcakes, but they were large, mildly seasoned and lightly sauteed, made of good backfin meat, with no bread filling whatever.

I'd stick to the mussels, though, so there's still room left for the other outstanding part of Bertha's repertoire: wonderful desserts prepared next door by Mrs. McKinnon, mother-in-law of the owner of Bertha's.

It would be hard to choose between the pecan-butter tart that is dense and chewy, barely sweetened, topped with plum preserves; or the buttery apple-and-sweet-potato pie that is light and custardy, in a good home-style crust, topped with real whipped cream.

Don't expect rapid or smooth service: the place is disorganized. There are not enough waiters to handle the sizeable crowds that gather weekend nights in the small restaurant that is composed of two adjoining townhouses built in the 1830s.

The owner of Bertha's (Bertha herself, alas, is merely a figure in a stained glass window) gutted the inside about 10 years ago, and created a charming, simple interior, mostly decorated with nautical artifacts and turn-of-the-century knick-knacks. Classical music plays in the background. Fireplaces in every room were blazing during our recent visit.

Bertha's is at Baltimore's old port of Fells Point, one of the city's most distinctive and diverse neighborhoods. It dates back to 1726 when William Fells came from Lancastershire, England, to start what was to become a major shipbuilding facility. The Constellation -- the first ship to be commissioned by the U.S. Navy -- was built at Fells Point. The port became known for the famous Baltimore clippers.

Later, successive waves of immigrants enriched the neighborhood even further. Bertha's is on a section of one street that is heavily Greek. If you take a stroll after dinner, you'll hear the strains of Greek songs wafting out of the nearby tavernas.

If you get there early enough, it's fun to explore the municipal markets that have lined the waterfront street for a century. Our children particularly enjoyed the tugs anchored at the end of the street.

If you plan to stop for dinner at Bertha's with children, get there early. Customers start backing up by 6:45 p.m. on weekends.