The journey begins at Paddington Station, where John from Mind the Gap Tours is waiting by the bear. We board the Reading train and, when most Windsor-bound tourists alight at Slough for a connecting train, we stay on board. We get off a few stops up the line at Taplow and head for John's office - a white van in the station carpark.
Soon we are freewheeling down country lanes on a 10km ride through Berkshire countryside.
A stop at Dorney Court, setting for films and TV murder mysteries, reminds us that the estates in this district belong to the seriously privileged. But thanks to English countryside access rules, we can venture behind the hedgerows to enjoy the scenery of the gentrified.
We follow a track through wildflowers and oak trees, along canals and finally the man-made Jubilee River which, John explains, was created not so much to honour the Queen but to relieve flooding from the Thames.
As John has promised, when we reach the Thames there's a great view of the castle which, because of its hilltop location, is actually hard to photograph from within the village. It was the view from the hilltop, of course, which prompted William the Conquerer to choose Windsor as the site for a castle west of London, one of four corners to guard the city.
Before we get there, John has another diversion - a tour of historic Eton Village. We pass the Queen's hole-in-the-wall - the only time she needs cash, apparently, is on Sunday mornings before church.
We peer into the college whose playing fields, John claims, were the nursery for many a European war. (It's a variation on the Duke of Wellington's supposed quote about his old school - that the Battle of Waterloo was won on the playing fields of Eton).
After a pub lunch, we make the short walk over the bridge to Windsor where we have a whole afternoon to inspect the castle. We will need it.
The flag is flying atop the 800-year-old Round Tower, signifying that the Queen is in residence. But happily she is not entertaining dignitaries so everything is open - the stunning 15th-century St George's chapel; Queen Mary's dolls' house with its intricate scale models; the state apartments with their collections of crockery, guns, swords, uniforms and their gilt-edged interiors: the Queen's guard chamber, the King's drawing room, the Queen's audience chamber, the fresco ceiling in the King's dining room ...
It is a palace of opulence and deference, but the castle is no museum, as highlighted on videos showing the Queen and Prince Philip hosting presidents and dictators at state banquets in St George's Hall or the Garter Throne Room.
The 60 Photographs exhibition in the Waterloo Chamber injects a jolt of realism to the surrounding fantasy. Many of the pictures are black-and-white and return us to an age that seems much longer ago than 60 years.
There's the innocence of young Elizabeth alongside Queen Mary and the Queen Mother at the funeral of King George VI in 1952; the optimism of her coronation; departing on the Royal Train; with JFK and Jackie in 1961; her obvious ease around horses and enthusiasm watching the Derby in 1988.
Contrast these with David Winsett's 2008 portrait capturing a sad ruefulness around her eyes. But, overall, the exhibition destroys the stereotype that the arc of the Queen's 60-year reign has gone from youthful exuberance to the disappointed old lady we often see on TV.
With a place like Windsor to escape to, it can't have been all bad.
CHECKLIST
Getting there: Korean Air has five flights a week from Auckland to London via Seoul.
Further information: Mind The Gap Tours offers guided bike trips to attractions in and around London including Windsor Castle and Hampton Court on vintage-style bikes with bells and baskets. The Windsor Castle tour includes return train tickets from London and 13km bike ride to Eton and Windsor from Taplow. Alternatively, take the Reading train to Slough and connect with the branch line to Windsor.
Geoff Cumming flew to London courtesy of Korean Air.
