This week I paid one of my quarterly visits to Fancy That of London, a shop on the Haymarket, a stone’s throw from Piccadilly Circus. There is no reason why any Times reader would have heard of this shop, let alone have entered it. Fancy That is only for tourists; and visited only by tourists. It sells teapots depicting Henry VIII and his wives, pillar-box and telephone-box moneyboxes and T-shirts bearing the slogan “My boyfriend visited London and all I got was this lousy T-shirt”.

It also sells, much more importantly, plastic models of the most famous buildings in London. There are models of Tower Bridge, the Tower of London, Buckingham Palace and hundreds of models of all shapes and sizes of the tower of Big Ben. This is why I visit Fancy That; by monitoring the souvenirs it sells you can follow the way foreigners see us; to understand properly what it is that they see as iconic about Britain.

This is because cities particularly, but countries, too, have buildings that encapsulate their identity — the Statue of Liberty, the Eiffel Tower, the Colosseum, Sydney Opera House, all these are the hallmarks of the cities and indeed the countries in which they stand. Watch any bad movie and you will see what I mean. It takes only a small architectural clue to position people in any major country in the world.

But how accurately do Fancy That’s models encapsulate a vision of Britain? Tower Bridge and the Houses of Parliament are clearly products of the 19th-century Gothic Revival. Both can be found on the front covers of holiday brochures from Manila to Miami. Both represent perhaps this country’s most powerfully distinctive architectural style.

The British Gothic Revival was stronger, went deeper, had a more spectacular expression than anywhere else in Europe. In part it was a reaction to our early, rapid and thoroughgoing Industrial Revolution. But it was more profound than that. It became an expression of national liberty and freedom, a distinctive way of building that set us apart from the autocratic states on the Continent and their “foreign” architectural styles. At a time when British technology led the world, many of its most important public buildings were being constructed in a style that had last been used 500 years before. Manchester Town Hall, the Natural History Museum, St Pancras station, and Glasgow University are all buildings designed for contemporary Victorian activity, governance, collecting, transport and education, but in a style that expressed a nationalism and confidence rooted in the achievements of the past.

The Tower of London is also a Gothic Revival building, whether we like it or not. By the early 19th century there was hardly a Gothic arch left in the ancient fortress. It was essentially a huge Georgian storage depot built of brick and fitted with nice, tidy sash windows. For the Victorians this was not good enough. As the repository of the Crown Jewels and the symbolic royal stronghold in times of war (and in peace, too) it needed to look old. Even the Duke of Wellington thought so. The great Victorian architects Anthony Salvin and John Taylor re-gothicised it. They turned it into a carefully created piece of medieval history; something that proclaimed to friend and foe military might and national independence, past and present.

Buckingham Palace, while not Gothic (what we see is Edwardian classicism of 1913), is still part of the Victorian image of Britain encapsulating the richest and most popular period of our monarchy. In fact, the Palace, the Victoria Memorial in front of it, The Mall and Admiralty Arch were built as a national memorial to Queen Victoria. The palace was thus intended to be a national icon celebrating the Queen Empress and her Empire.

So for the foreigner, a hundred years later, the emblems of Britain are still Victorian, springing out of that extraordinary period of economic success rooted in a strong sense of history and architectural independence.

Thus, it is a surprise in Fancy That to discover a modern icon taking its place alongside the oldies. The plastic composite souvenirs that combine Tower Bridge, with the Tower of London, Big Ben’s tower and Buckingham Palace now have the London Eye in the background too. It’s also possible to buy individual London Eyes and, of course, London Eye snow globes. For a new building to enter the Valhalla of national icons is rare. It is also good. It shows a dynamic living, successful country, not one fossilised as a historic relic of the past. The Eye, though, is more than just an eye-catching silhouette. It is also a distinctly British monument. After the Second World War architects in Britain embraced Modernism, an international style whose roots lay outside Britain. In this style were built the structures that the New Elizabethans needed for everyday life: telephone exchanges, civic centres, office blocks and towers of council housing. Not since the Norman Conquest had there been such a revolution in the style of public building. Not since William the Conqueror had there been such a determinedly alien style introduced to our shores. It brought us the government buildings in Marsham Street, London, and the Birmingham Bullring.

This international moment has largely passed and we once again see a distinctive Britishness in our architecture; a style that has grown out of our national architectural tradition. High-tech, the style of Norman Foster and Richard Rogers, the architecture of the Gherkin and the Lloyd’s building, came from this island. It is a style that springs from deep historic roots, from the engineering feats of the 19th century, from Paxton’s Crystal Palace and from Brunel ’s Paddington station. It grows out of the engineering ambition that pushed new materials to their limits and invented the iron-framed building and the railway. Certainly we have exported high-tech architecture all over the world, but we can lay claim to it as our own. The London Eye is a high-tech structure elegantly melding engineering and design, and as such belongs to this wave of new British building.

However iconic these great metropolitan structures may be, the essence of our national architectural style is found not in the big, brassy stuff but in every village, town and city in a series of building types that can be found only in Britain. Take the terraced house. This is a type of building found mainly in England and Wales. In France terraced houses are even called maisons Anglais. The success of the terrace is that it gives people the opportunity to have their small square of England. It gives external anonymity and conformity, but inside allows for the expression of individualism and eccentricity.

The parish church, too, is unique to this island. It is product of our own unique nationalised religion, half Protestant half Roman Catholic, a classic compromise celebrated in buildings which are themselves a compromise. Parish churches act as the repository of communal memory and the focus of civic pride and identity among believers and non-believers.

Or take the seaside town. Nowhere else does a cold, grey and windy climate combine with a love and a fear of the sea as in Britain. The seaside pier, the marine pavilion and the whole festive panoply of Victorian and Edwardian seaside architecture is an extraordinarily distinctive feature of our coast.

Few of these buildings will appear in Fancy That but they make up the backbone of our national architectural identity. While celebrating the arrival of new styles and new icons we should guard carefully our amazingly distinctive architectural inheritance. It is a vital and central part of defining who we are, and we ignore it at our peril.

Simon Thurley presents Building Britain on Channel 4 tonight at 7pm