Liverpool might as well be under 30 feet of volcanic ash as far as the ordinary American visitor to England is concerned, since it is one of the least known of great cities but one that well rewards the tourist.

This year its International Garden Festival, which runs through Oct. 14, has drawn many thousands, including some who expected the South Bronx, say, but who found instead a city more like New Orleans or Marseilles.

"People know us for the Beatles," said Hilary Oxlade, a volunteer guide for the Merseyside Development Corp., "and beyond that they guess we are full of punks and they suppose nobody here works very hard -- all that sort of thing."

Now a city of 580,000, it was chartered in 1207 by King John of Magna Chartafame. His Majesty told everybody to move to Liverpool but nobody did, to speak of, and the town rather dozed until the 18th century. American cotton used to float on barges down the Mississippi River on its journey to Liverpool and the great English factories, a trade that climaxed just before the Civil War.

The main point of the festival is to give the economy a happy jolt, and Queen Elizabeth herself opened the 125-acre gardens that have risen from a decrepit stretch of old shipping docks. Half the site will become a permanent promenade and gardens while the other half will provide a thousand home sites and various industrial headquarters.

The site was originally flatter than a two-day-old pancake but 600,000 tons of silt were raised from the docks and hundreds of thousands of additional tons of rubble and lumber were used to make rolling hills -- a mountain, one would say after trudging up one of the major viewpoints.

A little steam engine puffs valiantly through the gardens pulling open carriages stuffed with children, especially, since they seem to prefer the train to the study of labels in, say, the Australian garden packed with horticultural rarities.

There are 40 acres of British "theme gardens," devoted to alpine plants, heathers, roses, bog plants and so on.

People have queued up to go through quite small model houses with small gardens attached. As in the rest of the world, housing is costly now, and the days when "small garden" meant two to four acres are past.

Many nations have contributed small gardens. Germany offers perhaps a trillion daisy-type flowers in tints of yellow and orange with spikes of blue salvia sufficient to make the rash gazer wipe his eye. The Egyptians have some rosy columns, rather small, but suggestive of the great ones at Luxor, while the Greeks have white ones, hinting at the Parthenon. The Dutch have a windmill (modern, not at all the kind that Don Quixote battled) with three blades that are probably efficient.

The United States has a plot of one acre that in future years will show noble American trees, now saplings, as a memorial to men of the Eighth Air Force, based in England, who died in World War II. This solemn touch should restrain critics from saying very loudly that at present the effect of the memorial stone and the red geraniums is somewhat paltry, half-hearted and distinctly cheap.

C.Z. Guest represents America at this festival, with the title of commissioner general. She has found the effect beautiful.

Two Chinese gardeners, she has reported (in The New York Times), came over to help her water our "droopy pines." They were not droopy when I saw them, not that they looked like much, and it might be argued the blatant color of the geraniums is unnecessarily hostile for a supposedly peace-loving nation.

The Chinese, when not watering our droopy pines, managed to build a couple of exquisite pavilions, and they brought one of those large water-pitted rocks as a major ornament, which somebody managed to break the whole top off of, quite ruining its shape. Some say it can be glued back on, but this struck me as easier said than done. It would take many, if not all, the king's horses and men. The walks throughout the gardens are very wide but by no means wide enough to ensure casual strolling about. Every wheelchair of the Northern Hemisphere is present, and every tot in Britain arrived when I did. None got eaten by lions and few got lost; most of them circled their parents like ducklings except when making bold Danish-type forays through the countryside.

There are masses of begonias here and there, and sweeps of marigolds. Here and there you see tripods of sweet peas. The crowd, which you did not come to see, is nevertheless enchanting to watch. It is rare that so many humans (3 million are expected to have visited the gardens by October) may be seen so contented, so shirt-sleeved and so slow. If the gardens, as gardens, are far less than spectacular, still the engineering by which such vast fills have been made is impressive, and the promise for the future, when the scrub turns to noble forest along a great esplanade, is something to applaud.

The festival undoubtedly has lured thousands to Liverpool who ordinarily would have collapsed in Canterbury and let it go at that.

Liverpudlians are forever asking if one did not like Liverpool more than one expected to, and the invariable answer is yes.

This is not merely because Liverpool is poorly advertised in the books that tourists read before setting out, so that almost anything would exceed their expectations, but also because Liverpool has an easily detectable tone of open friendliness. It has the feel of Australia in this respect, and is well worth, as the guide books to France used to say, a detour.

Crack trains get here from London in three hours. A notable art gallery has the largest collection of paintings in England outside London, including just now "The Art of the Beatles" -- photographs of and by these singers and paintings and drawings by them, including a sexually explicit work by the late John Lennon that has titillatory value for the young.

The Anglican cathedral is the largest in Britain, and while late Victorian it is stunning in its mastery of great space, and one longs to swap the less impressive Washington Cathedral for it.

The Roman Catholic cathedral, circular and relatively small, has a handsome crypt. The main building has the merit of novelty, an excellent pipe organ and unimpeded sight lines. It is called Paddy's Wigwam in tourist literature, apparently in allusion to its conical roof. It is more substantial than the wigwams of our plains, however.

The pubs of the city are remarkable in carved woodwork of the last century. In one of them a men's bathroom of marble is an English monument visited by tourists of both sexes.

The club at which the Beatles sang is destroyed, but the site is marked, and across the street a statue of Mother Liverpool with three cherubs in her lap, said to be Beatles (one has flown) is fixed to a wall. It is virtually a shrine.

The vast Albert Docks, architecturally beautiful in soft pink brick, are being renovated as restaurants, shops, museums and apartments. They enclose a tremendous pool into which great ships once passed. It is like our Canal Square renovation only vaster and more handsome.

Many of the city's major buildings have the opulent air of a settled Edwardian dowager serene in her amplitude and unchallenged in her solid calm, albeit adorned with God's plenty in the way of tufts.

One sleeps like a log in such comfortable old hotels as the Britannia-Adelphi, dating from the days of steamer trunks and porters to lug them.

Although the armadillo is not native to this island, a restaurant by that name cooks such dishes as Veal Normande with flair. Or there is shepherd's pie, pa te' and tomato sandwiches in the pubs, even the ones without monumental loos.

A horrible thought occurs. Liverpool would be a rather nice place to live.