But luckily for the British capital, a river runs through it.
And for London's super rich, the River Thames will be an uncluttered highway to zip from party to party, from event to event in a flotilla of speedy yet breathtakingly expensive boats. Not for them the sweaty summer waits on the London Underground.
Companies like Protection Services International are just one of the many catering to the oligarchs, the sheiks and the just plain loaded who are coming to London games and demand top security and easy transport.
PSI normally concerns itself with making sure that Somali pirates stay away from super tankers off the Horn of Africa. But water is water, and celebrities are celebrities, after all. And with the Olympics ready to go in London, the River Thames suddenly presents a golden opportunity.
"It's a massive event, people from all over the world coming here. ...There are going to be certain threats," said David McIntosh, a PSI bodyguard. "Any Royal Marine commando can adapt and transfer our skills that we've got from Iraq, from working round the Horn of Africa doing the anti-piracy stuff, and also from doing celebrity protection in Leicester Square."
The Thames has already been in the limelight this year - starting with a flotilla of some 1,000 boats that marked the Queen Elizabeth II's Diamond Jubilee in June. But the river has always been the city's spine, the core around which its fortunes were built. It's the reason London became a maritime city, then a world city.
The Thames connects great royal palaces like Windsor Castle and Hampton Court. It links seats of power like the Bank of England and the Houses of Parliament as it runs 215 miles (346 kilometers) east through London into the North Sea through the broad Thames Estuary.
It's the viewing platform to best see the city and its sights - the London Eye, the Cutty Sark clipper ship and Tower Bridge, which is at the moment adorned with a huge Olympic rings to honor the games that take place from July 27-Aug. 12.
In sporting terms, the river has long been a venue for trials of endurance, such as the annual race between rowing crews from Oxford and Cambridge universities and the Henley Royal Regatta that draws crews from all over the world.
And for just as long, it's been the playpen of the super rich anxious to move about in style, says Robert Blyth, the curator of the National Maritime Museum.
"Historically, kings and queens would have traveled by river - the roads were rather uncomfortable and dangerous," he said. "It's a long time since we had a traffic jam on the Thames."
The Olympic Park in east London's Stratford neighborhood isn't actually directly on the river, but it is close. Some venues though, touch the river, including the equestrian venue at Greenwich Park.
London is set to become the alternative destination for the super yacht - the floating palaces that are deluxe hotels with staffs versed in perfect service, owned by people seeking someplace more novel than Cannes, St. Tropez or Monaco.
"They want a change from the milk run," said Benjamin Sutton, the director of communications for MGMT Yachts and Concierge. "It's the Olympics. Our river runs through the city and all the Olympic sites ... You can go to the south of France anytime!"
Yacht watchers will be on the lookout for the "Eclipse," the 538-foot (164-meter) ship owned by Roman Abramovich, the Russian oligarch who owns the Chelsea soccer club; the "Octopus," the 414-foot (126- meter) yacht owned by Paul Allen, the American Microsoft billionaire; and the "Leander," the 246-foot (75 meter) yacht owned by Britain's Donald Gosling, who made his fortune in car parks.
"It's like being in a huge luxury hotel," said Jim Gilbert, the former editor and chief of ShowBoats International, an industry bible.
Once those yachts have pulled in, they let the services come to them - which is where firms like PSI come into play.
It's not as if London has gotten suddenly more dangerous. But for someone like Abramovich, who is worth billions, his family could face security threats if they were crammed onto the Jubilee Line, a main artery to the games.
PSI offered reporters a demonstration ride on the Thames, offering a taste of how the super rich might get to their seats at the beach volleyball competition.
It started with champagne at the Savoy, London's elegant hotel. Then a trip on a rigid inflatable boat down the Thames followed the bubbly, a zippy excursion that could give Disneyland ideas on roller coasters and white water rafting. Envision ex-Marines re-living glory days with a high-powered boat to play with, you get the picture.
PSI declined to talk about prices - saying that depends on what the client wants and how complicated the security arrangements are.
At this level, talking about money is a tad crass, anyway.
But no matter what, they offer great scenery. The Thames will provide the images of London that viewers around the world want to see this summer and will remember for years to come.
"The river is the very reason for London," Blyth, the naval historian, said. "London exists entirely because of the Thames."