London is the one place on the map where the best advice is to leave the bike at the edge. The centre around Charing Cross and Trafalgar Square is a maze of one-way streets, bus lanes, taxis and tourists, and parking is limited and expensive. The city also has a congestion charge and a low-emission zone, whose rules for motorcycles have changed over the years, so check the current conditions for your own machine before you ride in. For a start and finish, a quiet side street or a secure garage on the outskirts is a better plan.
What you are stopping for here is history on a large scale. St Martin-in-the-Fields, a handsome eighteenth-century church with a tall steeple and a classical portico, stands at the north-east corner of Trafalgar Square, and its crypt hosts a café, a gallery and a brass-rubbing centre. It is famous for its lunchtime concerts and for its work with homeless people. Across the road, Nelson's Column rises over the square, with its bronze lions, and the National Gallery stretches along the north side.
The city has some 7.5 million people, and it is never quite finished with itself. Roman Londinium was a muddy trading post on the Thames, and the medieval city grew into a great port, burning down in 1666 and rebuilding in brick and stone. Westminster, a short walk south, holds the Palace of Parliament and the Abbey, where English monarchs have been crowned for nearly a thousand years. The riding here is entirely about getting out: the A3, A4 and A40 lead to quiet lanes in Surrey, the Chilterns and Kent, and a very early start on a Sunday morning makes it easy.
Fuel is available, but it is among the most expensive in the country, so top up on the outskirts. For a drink, a pub in the side streets off Whitehall, with its brass and etched glass, is as London as it gets. And when the light fades, the square is full of buskers, pigeons and people, and the lamps along the Mall glow.