Brick Lane and Princelet St

Today was the Brick Lane Festival. It didn't seem that different from any other Sunday crowd visiting the markets, though with the traffic taken away there was more room to spread, for the restaurant tables and the crowds alike.

Fifty or so years ago, I was taken to Petticoat Lane by my parents. I don't think we would have ventured up Brick Lane. Markets tended to be even more about entertainment then than now. Instead of today's blaring beats, there were the china salesmen, who could take a cunningly-interlocked 24-piece tea set and chuck it around in the air, while running through the familiar stand-up routine to which the audience can recite the punchlines (Everything I make goes towards the mother-in-law's holiday, and the more I make THE FURTHER SHE GOES).

Now as then, markets offer the novelty and diversion on which city life thrives. You can find some very different goods: the main attractions in Spitalfields and the lower end of Brick Lane are arty rather than practical or second-hand clothing, handmade jewellery and lighting. At the northern end, once you pass the area where the East London Line extension is being built, the market becomes more general, more second-hand. Here, among the batteries, bargain socks, toiletries, offcuts of flooring, cheap mangoes, cooking pots, mysterious tools and bits of electrical gear, bankrupt stock, ends of lines and things that might possibly have been helped off the back of a lorry, there's a whiff of continuity with that childhood visit here. And foods from all around the world: not just the curries on the Lane itself, but stalls offering dim sum, falafel, stir-fries, crepes, Ethiopian, Caribbean, paella, empanada - and some decidedly retro cupcakes.

The processes by which we got that diversity have not been without controversy. In the disused synagogue at 19 Princelet St, there are plans to open a Museum of Immigration and Diversity. Today was one of the few days this fragile building could be opened to the general public (last chance for 2007 will be through the London Open House weekend, 15/16 September.)

Surrounded by the discreet good taste of expensive restoration in Georgian Spitalfields (and less discreet or tasteful burglar alarms and estate agents' boards) No. 19, once you enter, is a shadowy, grimy space, here and there propped up on scaffolding. Daylight filters through coloured skylights on the narrow gallery, the dust-laden chandeliers, the painted boards commemorating the synagogue's donors, the fragments of lino and the stored away furniture.

In and around the space, the Suitcases and Sanctuary exhibition tells the story of the successive groups of immigrants to the area (Huguenots, Irish, Jews, Bengalis, Somalis), through the imaginative and touching contributions of local schoolchildren (most of them children of immigrants themselves), and some installations and artwork by immigrant artists.

The building is also famous for the room abandoned by its last caretaker. His life was explored in Rodinsky's Room, a fascinating parallel investigation of the facts and the myth-making surrounding his apparent disappearance. The prosaic truth, was unsurprisingly, sadder and stranger than the myths: a family's withdrawal into the remembered habits of the abandoned shtetl, while the community around them adapted to the "get on and get out" hustle of life for new arrivals in London. The last of the family, David Rodinsky, became a reclusive auto-didact. Alone in a little room above this abandoned meeting-place, he pursued his self-designed curriculum, that would perhaps have been understood and accepted by previous generations in eastern Europe, but was seen by his London contemporaries as strange, and ultimately mad.

In the large scale, the history of immigration is a collection of individual success stories, but with so much sadness along the way, as with the Rodinskys. So many memories deserve, like this haunting building, to be preserved.

And even more than buildings and memories, living refugees need help. Now.