Atmosphere: Hokey hacienda but casual.

Hours: Lunch, 11 a.m. to 3 p.m. daily. Dinner, 3 p.m. to 10 p.m., Monday through Thursday; 4 p.m. to 11 p.m., Friday and Saturday; 4 p.m. to 10 p.m., Sunday.

Price range: 80-cent snacks to $10.95 seafood dinners.

Reservations: Advisable at peak hours.

Credit cards: American Express, Visa, Mastercharge.

Special facilities: Highchairs and booster seats; ramp to restaurant but steps inside may make wheelchair accessibility difficult; limited on-street parking; garage parking available.

Casa Maria is the kind of place we usually go out of our way to avoid. It's one of three restaurants in the Washington area owned by Host International, a food conglomerate. Thinking that the only way Washington will ever have decent food is if enough small family restaurants bring it here, we make it practice not to patronize such food mills.

But we've found Casa Maria to be a family favorite for years now. The fun starts when you arrive. There is an endless recording of Mexican music playing softly over the stereo. Waitresses and waiters in ersatz Mexican costumes, the kind we've never seen in Mexico, greet and seat you in one of several rooms done up in probably the hokiest hacienda-modern decor you'll ever see. There are fake beams, fountains, Moorish windows, tile everywhere and incredibly bad paintings of idealized se nors and se noritas.

What really delights our group are the guitar players who stroll around the restaurant most weekends serenading diners. Every kid we've brought into the place thinks that's the height of swank.

The grownups, of course, thumb through the menu more concerned with price and portion size, yet you see them tapping their toes along with the music and smiling at the kids' apparent pleasure too.

But the bottom line for every restaurant is the food, and it is here that Maria's confounds, for some things are done very well but most dishes only get by.

Happily, the first pleasure of Maria's is also the cheapest: free fresh-daily corn chips and the wonderful tomato-based dip that comes with them. Absolutely first-rate.

During a recent visit our party of three adults and three children started on the chips and two appetizers, guacamole dip ($3.50) and cerviche ($3.95). It was perhaps the finest and tastiest guacamole we've had in this city--tangy, creamy and delightful--but not very much, considering the price. The cerviche, baby shrimp and chunks of cod marinated in a lovely blend of tomatoes, onions, avocados and lime juice, was wonderfully fresh but again too little for the tariff.

The big people moved on to crab and shrimp tostada ($6.50), one of the visual treats of Maria's. A mixture of shrimp, crab meat, mushrooms, cheddar cheese, sour cream, guacamole, olives and sliced tomatos is served in a huge pastry shell shaped like Ben Hur's gladiator helmet. It was tasty and good and the small folk enjoyed eating the helmet.

The kids worked on all the dishes but liked best the taco nacho ($5.75), a generous pile of corn chips heaped with beans and cheese, with shredded beef, lettuce, cheese and tomatoes on top. Not bad.

They were also big on the gordito burrito ($5.50), a burrito stuffed with chicken, beans, avocado and veggies that filled the serving platter and knocked the hunger out of all who tried it.

The crab and shrimp a' la puerto dinner ($9.50) was really just a wee casserole of fish and shrimp sauteed in garlic and shallot butter. I wasn't particularly happy with the dish, but it got a thumbs up from everyone else who tried it.

There are many other good dishes and some not so good at Maria's. The beer ($1.50) and sangria ($6 a pitcher) certainly passed muster, but desserts have never thrilled us. The flan ($1.25) is completely lost on us, the ice cream ($1) we can get elsewhere, and the mousse ($1.75) is both too small for the price and topped with that spun white cotton that comes out of a can.

Yet we'll be back. Where else can six eat and drink for $58.49, hear the soft strum of guitar music and see a Mexico that never was and never will be?