The one thing the travel books don't mention about Las Vegas is that it is dry -- a kind of dryness that just isn't conceivable in misty, foggy, humid Britain. Within days of arriving, my eyes stung from the constant cycle between hot desert air and the artificial chill of air-conditioning. Surrounded by fountains, water slides, pirate ships and swimming pools, I was slowly desiccating. Wearing contact lenses was almost impossible. I started moisturising three times a day.
Perhaps the books don't feel the need to point out the obvious - after all, Las Vegas lies in an arid basin of the Mojave Desert, with only 4.5 inches of rain a year and summertime highs of well above 40°C. If you drive out of the city, it quickly turns into the Wild West out of Central Casting: rasping animals, parched sands and suggestive cactuses.
Further out, towards the Grand Canyon, in the state of Arizona, the bright white of the Hoover Dam and the unyielding sapphire of Lake Mead clash almost obscenely with the burnt-out scree around them. Again, to a Briton, the landscape is utterly alien - vast, ribbon-like dunes with no trace of human intervention. There must be swaths of sand here that no one has ever stepped foot on.
Most people talk about the overawing scale of the canyon but few mention its stillness. There's barely any birdsong; creatures that live in the desert can't waste energy on screeching and squawking. This is the stillness of the earth before human beings arrived, with their neon lights and traffic jams and Tesco Metros; and, on the timescale of this ancient place, it won't be long before that stillness falls again. Our species is a geological blip.
A few more moments of reflection in this place makes it clear that humans are doing their best to hurry themselves into extinction. At Grand Canyon West, the banks of the Colorado River (the thundering force that carved this 277-mile-long scar in the ground) are discoloured from years of successive droughts.
In November last year, Lake Mead - the largest reservoir in the US, lying 30 miles south-east of Las Vegas - dropped to its lowest level since it was filled in 1937. A study by the Scripps Institution of Oceanography found that there was a 50 per cent chance that the lake would run dry within a decade.
Wilfred Whatoname, chief of the Hualapai tribe - the Native American custodians of the Grand Canyon West area - could not hide his concern when I met him earlier this year. As a huge feather fluttered in his long hair, we stood on the Skywalk, which overhangs the canyon, and he told me of his battles with government departments to keep the tribe involved in the protection of their sacred land.
Some progress has been made. In the first years of the new millennium, Patricia Mulroy of the Southern Nevada Water Authority paid residents $1.50 per square foot to replace their lawns with gravel and asked golf courses to dig up their greens. This cut water use in Las Vegas by almost 20 per cent between 2001 and 2008. Yet that's not enough, particularly for a city growing past two million residents (and which had 37.3 million visitors in 2010).
Perhaps these are its last days: it's hard to see how it can last in a century of water wars and with the end of cheap air travel imminent.
Of course, the idea of Las Vegas - gaudy, gluttonous and over the top - gains extra piquancy from its setting. The whirring, flashing Strip laughs at the notion that you wouldn't build a city full of fountains in a desert, while the two soaring bronze towers of the Wynn - the latest mega-resort hotel - might as well be a couple of giant fingers stuck up at puny nature.
At least the resort is honest in its artifice, making no apologies for its 1,000-item breakfasts and 6lb burrito challenges and the touts' delightful habit of shoving flyers for prostitutes into your husband's left hand while he's holding yours with his right.
That I liked Las Vegas despite all this surprised me. The whole place seems such a perfect metaphor for early-21st-century western decadence, down to the cracked paint of the older hotels and the dozy lions in the MGM lobby. This is also a place where the number-one tycoon, Steve Wynn (yes, he named his hotels after himself), is best known for putting his elbow through a £75m Picasso, just before he was due to sell it to a hedge-fund boss. His extravagant gesture ruined what would have been one of the world's biggest art sales (and come to think of it, an elbow through a Picasso isn't such a bad metaphor for Las Vegas).
We ate the 1,000-item breakfast, by the way. If you've ever wondered whether gelato, sushi, pancakes, marshmallows, curry and bacon belong in the same meal, they don't.