The Nazis saved Jewish culture in Czechoslovakia. But only its artifacts, not its life. With a macabre sense of history, as the SS rounded up the Jews of Prague, herded them into cattle trucks and sent them off to the gas chambers, they made meticulous efforts to collect and preserve the treasures of the great Prague ghetto. For what? For a Museum of Jewry "to commemorate the decadent culture of an extinct race".

Before the Second World War, Prague had one of Europe's most thriving Jewish communities, numbering 45,000 souls. By 1945, only 3,000 were left and today, since emigration to Israel, the figure is even less. Instead of a vibrant living community, Jewish Prague now offers as its most intriguing sight its bizarrely overcrowded cemetery, crammed higgledy- piggledy with 12,000 tombstones beneath which lie a far greater number of graves. That and a highly evocative and diverse collection of synagogues and meeting halls, and the sacred treasures which eventually did make it to a museum, the State Jewish Museum set up by the Czech communist authorities.

Not that the Jews had had it easy up till Hitler, no way. Their long Bohemian history is spattered with pogroms and victimisations and most of the Prague ghetto was razed and redeveloped by sanitising civic reformers well before the Nazis set about their evil work. Latterly called Josefov, the ghetto had existed for seven centuries, whilst the beginnings of the Jewish community go right back to the city's tenth century foundation.

In 965 A.D. Ibraham ibn Yakub, a Jewish adviser to the Caliph of Cordoba, came out of the high Islamic civilisation of Moorish Spain to survey the Northern Europe of the Dark Ages. At the new Slav city of Prague he found a prominent trading centre, a crossroads of the east-west traffic from Kiev to the Rhine and the north-south Amber Road from the Baltic to the Adriatic. And he recorded numerous Jewish merchant caravans.

Along with other traders, many of these Jews saw Prague as a good place to set up shop. Always under suspicion, at first required to wear yellow cloaks, then declared "prisoners and slaves of the Holy Roman Empire", in the 13th century they were corralled into a ghetto between the Old Town (Stare Mesto) and the River Vltava. There they had to stay for five centuries, and they were not allowed to exert their copious energies and talents in administration, politics or the military. They were left with the worlds of money, the mind and the spirit. By day the Jew was engaged in trade and money-lending, medicine or music. In the evening, he bolted his door seven times, left the hurly-burly behind, and pored over the holy scriptures and the Talmud.

On the sabbath he went to the temple; from this medieval period there survives the oddly-named Old-New Synagogue, built in the 14th century and now rated the oldest one in Europe. Despite persecution, business proceeded, and through the Renaissance Jewish wealth and influence increased, until that creative age brought forth the two most celebrated figures in the ghetto's history. Given the lives that the Jews led, it is no surprise that one was a financier and the other a scholar.

The scholar was Rabbi Loew whose long life, 1512-1609, spanned a legendary Prague era, fantastical times filled with alchemists' and astrologers' delusions and the outlandish claims of early scientists. Rabbi Loew evokes the spirit of this age with his Golem, a creature of mud and clay which could be brought to life to do good deeds. This benign precursor of later malicious mythical automatons like Frankenstein could be enlivened by the word "Shem" and sent out to protect the Jewish community, to discover crimes and to prevent them. More like Batman really - Batman of the Ghetto rather than Gotham.

One version of this legend has the revered Rabbi, cabbalist, astronomer and magician going down to the Vltava one dark night, clothed in white, to create the Golem with the chanting of spells out of the four elements - earth, fire, air and water. That Jews, even eminent scholars, should desire a magical protector is both a sign of those superstitious times and a reflection of the insecurity they felt, though some joke that the Rabbi really wanted a servant around the house without paying wages. There was a hitch: golems need regular instructions or else they run amok. The story has it that after the Golem rampaged around Rabbi Loew's house one night, he removed its spark of life and laid it to rest under the roof of the Old-New Synagogue.

The financier was Mordecai Maisel, who became treasurer to the King and in the 1590s built Josefov its Town Hall and the Maisel Synagogue, both of which survive. Maisel is one of the most celebrated inhabitants of Josefov, both by his position and by his beneficence. A 1592 eulogy proclaims: "From his property he built the High Synagogue for glory and beauty and donated it also several Torah scrolls with gold and silver accessories of rare work. He also built a public bath and a ritual bath; further he built a home for the poor and suffering and had all public spaces in the Jewish Town paved with stone - all that with his own money and at his own expense. Moreover, he had a large synagogue built, of such splendour that it has no equal anywhere...And yet another thing shall I tell: the sum of money expended by the dear and honoured Mordechai Maisel in the past two years on the construction of the said synagogue, all aids and loans, together with the dowries of the daughters of his neighbours, attains more than twenty thousand thalers."

Which must have been a lot of money. Nevertheless, as was typical of Europe until the 20th century, this splendour shone forth amidst squalor. Some Jews were very rich, many were comfortable, but most just scraped a living. As was also typical of past ages and all religions, rich patrons funded the creation of exquisite sacred objects. The surviving ones in Prague today date from this late Renaissance period onwards

They are gathered now in the State Jewish Museum, together with artifacts from all over Nazi-occupied Europe which the ghoulish SS curators had collected. The Museum in fact comprises all the historic buildings of the ghetto; it is the Maisel Synagogue which houses the magnificent metalwork collection, the sacred gold and silver treasures of the Czech Jews. Notable amongst them are the gilded silver crowns, head-pieces and breast-plates created to adorn the Torah, the sacred Hebrew Book of Law, central to the faith and believed by many Jews to recount every event on earth - past, present and future.

The 18th century Habsburg Empress Maria Theresa finally abolished the restriction to the walled ghetto and henceforth Prague's Jews were free to live in any part of the city. It was not only the living who were glad of extra space. By this time, the Old Jewish Cemetery was bursting with tombstones, some 12,000 in all, piled and stacked against one another as more and more dead were buried in the same spot. The number of actual corpses was far higher. It was a case of "Roll over, Shelomo" and make way for another one. With standing room only by then, the last burial occurred in 1787. Today it looks much as it must have then, an extraordinary and chaotic accumulation of sacred Hebrew-inscribed stonework. Some commentators have gone so far as to call it one of the world's ten greatest sights. This is stretching things a bit - better to call it uniquely, eerily fascinating.

Despite the new freedoms, completed in the revolutionary year of 1848 when all official discrimination was swept away, the Jewish Town continued to be crowded. Living conditions got worse if anything. Josefov was over-populated and noisome. Wrote an English traveller in 1857: "It is crowded with horses, traversed by narrow streets not remarkable for cleanliness, and has an uninviting aspect. Your sanitary reformer would here find a strong case of overcrowding." Within fifty years, so they did, and demolished the lot save for six synagogues, two halls and most of the cemetery.

Josefov's denizens were dispersed around town, the wealthier amongst them returning to inhabit the posh newly-built apartment mansions. In one of these lived the Kafka family, in which father Kafka domineered and humiliated his little Franz and unwittingly created a great paranoid novelist (though we'd never have known it but for his friend Max Brod who saved the manuscripts).

Josefov was now chic, nowhere more so than in the new thoroughfare of Parizska, which both in name and aspect exemplified the Parisianisation of the quarter. An elegant avenue then, frequented by the carriages of the Bohemian gentry, it is swish now too, accommodating those perennial seekers of a good upfront address, the international airlines. Between these and the modern Hotel Inter-Continental on the River Vltava embankment stand the few remaining synagogues and meeting halls of a millennium of Jewish Prague.

As tourism booms in today's Prague, Josefov has been spruced up. The Pinkas Synagogue, built in 1492 by one of Prague's most distinguished families, the Horowitzes, has been turned into a memorial for all the Czech Jews lost in the Holocaust. Their 77,927 names are inscribed in red and black ink on the walls. The quarter's old sobriquet of the State Jewish Museum has been rejigged to the Museum of Jewish Life. This celebrates a once vital culture, but mercifully far from an extinct one, as the sick Nazis had so confidently intended.