Hitler's luftwaffe destroyed much of old London. But it also uncovered new evidence of the city's ancient history. The bomb creaters proved tresure troves for archeologists who found tools, weapons and art works dating as far back as 250,000 years, when primitive men hunted animals now extinct along the Thames that had not yet taken its present course.

The Biltz thus gave rise to a growing historic awareness as well as a great many deplorably ugly Modern buildings.

The two come together in the exciting Museum of London, which opened a few months ago. It is part of the Barbican, a new "city-within-the city," built on the World War II rubble of an old neighborhood, a stone's throw from St. Paul's cathedral.

The Barbican is one of those "radiant city" schemes so fashionalbe in the '60s - 46 acres of concrete sprouting high-rise apartment and office buildings in a tangle of platforms, elevated walkways and ramps, featuring a square "lake" and some welldrilled greenery, and embracing (or strangling) some antiquities such as a stretch of the old City Wall, Roman ruins an poor old St. Giles cripplegate church.

The plate is as chilling and godforsaken as most other such high-rise invasions into Europe's old city centers. Despite the curving ramps across historic streets, the Barbican is all but inaccessible to the unintiated (the signs compound the confusion), and few bother to get initiated. The offices and apartments are half-empty.

The Museum of London is one of the Barbican's cultural offerings. The scheme also includes a school of music and drama, a concert hall and a theater.

I can tell you nothing about the museum's exterior architecture. It is an undeistinguised and undestinguishable part of the Barbican's disharmonious architectural potpourri - a piece of the concrete tangle supporting a black glass tower which, however, has nothing to do withe museum.

Once you managed to get inside, the museum is a near-perfect delight.

Only in a few rooms does architectural exhibitionism overwhelm the museum exhibits, as it does in most recently designed museums. In London, the architects (Powell & Moya Partners) seem to have worked closely with exhibit designers (Higgins Ney & Partners).

The architecture serves the display and helps people enjoy them. You follow the flow of the exhibits in a pleasant downward spiral. On the whole, the museum's light level is agreeably low so special displays can be highlighted wothout glare. (It is at times a little hard to read the labels, though.)

There are surprising new views and moods behind turns and partitions. There are several windows that afford glorious views on the city. One of them - just at the point where it fits into the story line - looks out on the excavated City Wall below. THere are varied and pleasant floor surfaces to avoid "museum feet." The provisions for handicapped to Sam Gallop, a leader of London's organization for the handicapped.

The display is a smooth blend of historic artifacts from prehistoric tools to souvenirs of the suffragette battle some decades ago, and clear, modern graphics. The museum, which grew out a merger of the old Guildhall Museum and the old London Museum in Lancaster HOuse, presents a vast number of facts and items, but nevertheless tells a coherent story at a pace that kept me absorbed for more than two hours.

At the model of Late Stuart London, where you are shown the origin and spread of the Great Fire of 1666, you also feel the heat (by means of a heat lamp. (At other displays you hear appropriate sounds and music. On the whole, however, the displays are devoid of the gimmicks some museums lately find necessary to hold their audiences. The Museum of London seems equally popular with schoolarship rather than showmanship.

The most glamorous objects on display, no doubt, are the paraphernalia of "Ceremonial London," including the Lord Mayor's opulent State Coach, which is still being used for the annual swearing-in ceremony. The glided carriage is parked dramatically in a pool which both mirrors it and keeps the old wood sufficiently humid.

But traditional pomp aside, the emphasis of the show is not on London so much as on Londoners - on the evolution of urban life over the past 2,000 years. In that, the museum is unique and uniquely fascinating.

"The city is the people" and in these days of urban sprawl and disintergation, of anonymity and the lonely crowd, it seems particulary important that cities and citizens are re-connected with their past. The preservation of historic buildings is vital in this respect. But by showing us the life and times that brought forth the old buildings, the Museum of London gives the historic preservation movement a new and vital dimension.

It provides more than a vivid history lesson. it seems well on the way to instilling visitors with a sense of pride and a sense of belonging. And I was glad to see that the museum is making energetic, although as yet insufficiently funded efforts to reach out into the schools and provide training.

I may be optimistic, but I beleive that today, with the impact of the Museum of London and the trend toward citizen participation, the people of London would not let another Barbican rise in their midst.