I'm not going to pretend that I was relishing the prospect of forgoing a long, lazy Saturday-morning lie-in to lead a walk from the Design Museum to Wapping Hydraulic Power Station on the opposite side of the Thames. For one thing, I was exhausted, having spent most of the previous day crawling around a gallery floor gaffer-taping computer wires into place as we raced to finish an exhibition installation. For another, I wasn't simply going on the walk; I had been asked to lead it, which meant that I was expected to discourse intelligently and imaginatively on whatever we saw along the way.

That was the real problem. The reason I had agreed to the walk was that I was asked to do so. I realised that I had shockingly little to say - intelligent, imaginative or otherwise - about the history of the area around the Design Museum. Prepping for the walk - or so I told myself - would be a great way of learning about it.

It wasn't as if it was likely to be dull. The route was filled with touristy totems such as the Thames and Tower Bridge, architectural coups such as Thomas Telford's radical 1820s design for St Katharine's Dock and the pop-culture frisson of Derek Jarman having lived and worked in a Butler's Wharf warehouse beside the Design Museum at the turn of the 1980s - at the same time that Bob Hoskins and Helen Mirren were filming The Long Good Friday across the river in what was left of Telford's docks.

A couple of weeks beforehand, I assembled an appetising pile of London history books: from Ben Weinreb and Christopher Hibbert's The London Encyclopedia and Peter Ackroyd's London: The Biography to anecdote-rich extras such as Jarman's Modern Nature. Needless to say, as the walk approached, I was far too busy to have enough time to dip into them.

The only solution was waking up early on the day of the walk to plough through the books. By then, even my memories of early-1980s Sunday evenings in Jarman's studio were palling. He often threw open his warehouse to an assortment of performance artists. Some were great, others interminable. The friend I hauled along to a particularly dire one (the details are mercifully hazy, but the performer was heavily pregnant and an oily chain was involved) still grumbles about it 20 years later.

· As I set off for the Design Museum that Saturday morning, I was torn between feeling sorry for myself for having been silly enough to have agreed to lead the walk and sorrier still for the poor sods who'd be walking with me.

But then I read the history books. Missing my lie-in had been worthwhile after all, because the history of the area was so much richer than I'd expected. Take St Katharine's Dock. A wasteland until the 12th century, when Queen Matilda built a hospital and houses for the poor there, it became a buccaneering free-trade zone on the fringes of the City in the 15th century and, centuries later, everything from sugar and tea to live turtles was winched out of ships' holds there to be stored in Telford's state-of-the-art docks.

Or take Wapping. Marshland until the 16th century, it then became the playground of the navy's unruliest sailors. By 1750, there were 36 taverns on Wapping High Street alone. The regulars at one, the Prospect of Whitby, were so notorious that it was nicknamed The Devil's Tavern. And while 19th-century convicts awaited transportation to Australia in the cellars of the nearby Town of Ramsgate inn, Isambard Kingdom Brunel was building the first underwater tunnel using a tunnelling shield invented by his father Marc between what are now the East London line tube stations at Wapping and Rotherhithe.

Even Rotherhithe had its moments. The birthplace of Jonathan Swift's Gulliver, it was also the home of The Angel, a 17th-century inn with a smuggler's trapdoor (for speedy entries and exits) in the kitchen. Just along the river is Bermondsey, which was once a spa resort for wealthy Londoners. Samuel Pepys loved to stroll in its 17th-century pleasure gardens, but by the 19th century Bermondsey had spawned the slums where Dickens set his most squalid scenes.

Thanks to my morning's reading, I set off on what turned out to be a really enjoyable walk. Since then, whenever I've looked out of my office at the Thames, I have pictured the Brunels tunnelling beneath the water or smugglers slipping ill-gotten gains into The Angel. On the site of Bermondsey council estates, I see Pepys strolling around the pleasure garden. However, I still can't think of Derek Jarman's early-1980s studio without hearing my friend grumbling.

Any other area of London - or most other places, come to that - have equally rich social histories. But like those of Rotherhithe, Bermondsey and Butler's Wharf, their histories are mostly hidden. It's easy enough to find out about the momentous events that happened at Tower Bridge or St Katharine's Dock, but not about the places where we're likelier to live and work.

As we can't all be expected to memorise the contents of The London Encyclopedia or Ackroyd's biography of the city, there should be ways of bringing the social history of different areas to life. More blue plaques would be one solution. I love walking along London streets and looking up to see a blue plaque telling me that this poet or that painter once lived there.

But there are fewer than 800 plaques in the whole of London, and the only other city to have them is Liverpool. Birmingham, Portsmouth and Southampton will soon introduce them, but that's still only five cities. And much as I would like to see more blue plaques, there must be other ways of conveying how an area has changed over the years: maybe by describing, beside street signs, the type of people who have lived and worked there in the past.

If not, people may start telling their own versions of local history. The art dealer Maureen Paley has a white marble plaque on her house on Beck Road, east London, dedicated to a woman called Jane Gifford. I had always assumed she was an obscure social reformer until Maureen explained that the plaque was a legacy of an exhibition she had held in the mid-1980s.

· The exhibition was of the work of Braco Dimitrijevic, an artist who commemorates apparently inconsequential people: such as the stranger he spotted in Hyde Park and turned into a sculpture for the Serpentine Gallery. When he exhibited with Maureen, she was using her home as a gallery; as one of the first in east London, it will surely sport a blue plaque one day.

But Dimitrijevic wasn't interested in dedicating his plaque to Maureen or any of the future Turner Prize-winners she was exhibiting. Instead he chose Gifford, whose only claim to a place in local history was that she had once rented a room from Maureen. Yet there is her name on the plaque today - the only visible sign of Beck Road's history.

· Alice Rawsthorn is director of the Design Museum.