THE best thing about London is there's so much to do. And that's the worst thing about London, too. It's overwhelming.
You either end up just reverting to the standard list – the Tower, the palace – or you try and pack too much in and spend hours trapped on the Underground. You might not get tired of London, but you can easily find yourself worn down by it.
It's worth, then, slimming down the itinerary, and looking past the usual tourist magnets. You'll spend less time getting to places and more time enjoying them, and just a little digging will reveal gems that most people never see.
One such gem is the Isokon Building, on Lawn Road, and it's a jewel hidden in plain sight, on a perfectly ordinary suburban street a couple of minutes' walk from Belsize Park Tube Station.
So unexpected is it among its neighbouring houses with their perfect gardens that it's easy to miss, but, once seen, its impact is immediate and lasting.
The Isokon Building is a block of flats, essentially, but it's so much more than that. Long, severe, its monolithic concrete reinforced frame gleaming white, its planes emphasised by the rounded curves of the stairways that access each of the four floors, with projecting balconies running its length, the Isokon remains daring and visionary.
At nearly 90 years old (it opened in 1934), it still belongs in the future, and feels so much younger and fresher than so many more recent designs.
The building was the brainchild of Molly and Jack Pritchard, a couple who sought to break the conventional bonds of their English middle-class upbringing. They met at Cambridge University where Molly, later to practise psychiatry in Harley Street, was studying medicine and Jack engineering.
They married in 1924. Jack, working for the Estonian Venesta Plywood Company, travelled widely, becoming influenced by continental modernism, and he and Molly shared progressive ideas on matters such as education and communal living.
Acquiring the site on Lawn Road, they became dissatisfied with their original plans for the space. It wasn't until they met the Canadian architect, Wells Coates, that their hopes for the site took shape.
Coates had no formal architectural training, but he possessed a passion for design and a fascination for how the elements of design fitted with each other. Gaining commissions for small projects allowed him use the most modern of materials, such as plywood, in pared-down designs within minimal spaces.
It was this approach that drew the Pritchards to Coates. Like them, he was concerned with a planned future, and was able to answer Molly's questions regarding the way people wanted to live and the streamlined, minimalist, liberating framework needed to make living as pleasant as possible.
The Isokon Building was the result of the collaboration. Young, single, professional men and women were the target market, people looking for a sense of freedom, unhindered by too many possessions, free of domestic drudgery.
The flats – more than 30 in total – are still in use, and so cannot be viewed, but a museum within the building gives an insight into the ideas that shaped the Isokon and the furniture designs that emerged alongside it, as well as showing one of the original – tiny – kitchens.
As beautiful as the building itself is, much of its fascination comes from its occupants, especially those who lived there before and during the Second World War. Emigré design luminaries such as Walter Gropius and Marcel Breuer, novelists like Agatha Christie and Nicholas Monsarrat, and at least four Soviet spies.
The Isokon Building is an exciting, thrilling place to visit, a vision for living, dramatic and bold, and not without a sense of mystery and intrigue.
And conveniently close to 2 Willow Road, Erno Goldfinger's modernist home, now owned by the National Trust - another of London's treasures if you take the time to look beyond the standard fare.
