Britain's Prime Minister David Cameron and his wife Samantha have their family home here and, if you'd like to share their experience of life in an elegant family home overlooking one of London's lovely garden squares, you can do so via Uptown Reservations.
Later William continued his schooling at Eton College, a 10-minute stroll over the River Thames from his grandmother's place, Windsor Castle.
The College, founded in 1440 by King Henry VI to provide free education for 70 poor scholars, conducts guided tours during the holidays, bookable through the Eton College Gift Shop on the High Street, where you can also buy an Eton boater.
While you're there you should also visit Windsor Castle - if the Queen is in residence you'll see the Royal Standard rather than the Union flag flying from the flagpole - which is where William had his 21st birthday party. It is open to the public and is home to a daily Changing of the Guard, Queen Mary's Dolls' House (the biggest in the world) and St George's Chapel, built in the English perpendicular style and famous for its stunning fan vaulting.
Kate went to school further west, in the beautiful Wiltshire Downs, at another prestigious school, Marlborough College. The school is not open to the public, but you can paint your own wedding commemoration mug at its annual July summer school and the Blackett Observatory sometimes opens to visitors.
The two actually met at the University of St Andrews in Fife on the eastern side of Scotland, founded in 1413, making it the third oldest university in the English-speaking world.
A William and Kate Tour would have to include a peek from outside at their joint hall of residence, St Salvator's, which offers great views over the Bay of St Andrews and has a famous foam-and-flour fight for new undergraduates on Raisin Monday every November.
The two also shared a student house on Hope Street and had romantic strolls along the edge of the North Sea on West Sands.
Even if you're not a golfer, while you're there make a pilgrimage to the famous Old Course at St Andrews Links, Home of Golf and one of the most famous courses in the world.
The actual engagement announcement was made from Clarence House in London, official office of the Prince of Wales and the Duchess of Cornwall, where Kate and William gave their first joint interview.
It opens for tours in summer, but you can catch a glimpse of it by strolling up the Mall from Buckingham Palace to Admiralty Arch, passing on the way St James's Palace, where the young couple held a photocall for their engagement. Turn up to Pall Mall to see the front, one of the few remaining Tudor gateways in London, guarded by soldiers in sentry boxes.
The Middleton family live in the village of Bucklebury, West Berkshire, within easy reach of Newbury Racecourse, home of the Hennessy Gold Cup, and the town of Lambourne, famous for its training stables and studs.
You can see the horses training early in the morning from high on one of two famous National Trails, the Ridgeway, the oldest road in England, made of white chalk. Also nearby is the Thames Path which goes past Kate's local town, Reading, on its way from the source to the mouth of Britain's most famous river.
The stately home Highclere Castle stars in the TV series Downton Abbey and is open to the public.
Kate dabbled briefly in women's rowing, when she joined a crew called The Sisterhood who were rowing the Channel for charity and practising on the Thames between Chiswick and Hammersmith.
Chiswick is one of London's prettiest - and most expensive - riverside suburbs, home to Lord Burlington's stunning neo-Palladian villa Chiswick House and Syon Park, London home of the Duke and Duchess of Northumberland.
Hammersmith, meanwhile, is famous for its gorgeous riverside pubs, such as the labyrinthine, 18th-century hostelry The Old Ship.
William, on the other hand, preferred the favoured royal sport of polo: the classic venue for this is the Guards' Polo Club at Smith's Lawn near Ascot, Berkshire, where the Cartier Polo Championship each August is one of the best celebrity-spotting events in Britain.
Before she joined the family firm, Kate worked for a while as a junior buyer at the popular British boutique chain, Jigsaw. Kate worked in the Kew branch, however the branch to visit is at 126-7 New Bond Street, designed 15 years ago by the super-minimal architect John Pawson and still a haven of tranquillity.
Then take a little stroll down London's classiest shopping street, making a diversion onto Albemarle Street to see Garrard & Co, which claims to be the oldest jewellers in the world and was the source of Princess Diana's famous sapphire and diamond engagement now - after being secretly carried around in William's rucksack in Kenya - being proudly worn on Kate's ring finger.
Note the royal crest outside (see Royal Warrants, below).
Kate and William's partying days moved effortlessly from discreet private members nightclub Boujis, handily placed just opposite South Kensington tube station, to Mayfair and the tropical ambience of Mahiki where Kate would have sat in a Princess chair sipping Lovers' Cup cocktails in the Aloha Room.
Later, the young royal set moved to the bar du jour, Whisky Mist, at 35 Hertford St, off Park Lane.
St James's Palace and its environs provide some of the most charming walking in London, because it was one of the earliest parts of the city to be developed, mainly by friends of the party-loving Charles II in the 17th century.
Go Royal Warrant-spotting on some of the marvellous old shops, from Berry Bros & Rudd, the wine merchants, to Lobbs the shoemakers, who hold shoe lasts for Prince Charles, and Locks the hatters.
Further east, on Queen Victoria St, heading towards the City of London, is the Royal College of Arms - a rare Jacobean building remaining in London - which will now be hard at work designing arms for Kate.
Also in London, of course, is Westminster Abbey, burial place of the royal and famous for many centuries, where William and Kate will be married on April 29.
The young Windsors have announced their intention to begin their married life near his RAF base in Wales, and will live on the island of Anglesey.
The island not only has some of the most stunning beaches in Britain, with white gold sand, rock pools and hardly anyone there, but is also home to the station with the longest name in the world at Llanfair, or Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, to give it its full name.
While they're there Kate and William might tackle Britain's highest mountain, Snowdon, by taking a trip on the year-old Welsh Highland Railway from Caernarfon (where his father was invested as Prince of Wales in 1969) to Pont Croesor, where you can pop off halfway, climb up to the top of Snowdon, and walk down again.
From the top, if it's a fine day, you'll be able to see the splendour of Wales, an appropriate vantage point for the future Prince and Princess of Wales.
Further information: See visitbritain.co.nz.
