Letter from Nazca, Peru: It rains for half an hour every two years here in Nazca, a desert town 250 miles south of Lima, so the sands are even drier than those of the Sahara, writes Patrice Harrington.
We came here to see for ourselves whether or not the famous Nazca lines etched into the sand are being ruined by idiots driving over them, as was indicated by aerial photographs taken in July; only the second set to be commissioned by the Government since 1973.
After eight hours on a bumpy bus from Lima (with precious few and grudgingly given toilet breaks), we were hoping not to be disappointed.
More than 2,000 years ago - before Christ, before Incas - Nazca tribes people drew giant shapes and pictures into this hard, brownish sand, burrowing just 30 cm from the surface to reveal the whiter sands below.
The absence of rain and the plentiful winds that sweep the patterns clean of debris have combined over millennia to make it the most impressive natural sketchpad imaginable.
But the drawings - of a monkey, a spider, a hummingbird, an "astronaut", to name but a few - are so large in scale (up to 1.2 miles long) that they can only be seen from the skies. The Pan American highway cut the figure of a lizard in half when it was constructed in 1938. But at least they could plead ignorance. These days, it would appear that truck drivers are knowingly taking a short cut over the drawings to avoid toll stops.
The mysterious pictures were scratched out long before the Wright brothers first took to the skies, so the question of how they were created, and for whom, has been the focus of wild conjecture since trans-Andean pilots first flew over them in the late 1930s.
Some thought the lines were part of an ancient irrigation system. Others still believe they are extra-terrestrial landing strips. The most famous Nazca researcher of all, German mathematician Maria Reiche, thought they matched the constellations and most likely served to mark sowing and harvest time.
But astronomers have scoffed at Reiche's theories, saying the patterns bear no relation whatsoever to the stars above us.
They probably aired their counter-arguments well out of earshot of the locals here, who have erected a museum in Reiche's memory and still speak of her with reverence.
The blonde researcher, nicknamed the "guardian angel" of the Nazca lines, spent 50 years examining them through her horn-rimmed spectacles and guarded the 280-square-mile protected zone almost single-handedly until her death six years ago at the age of 95.
Her devotion extended to brushing the lines with a broom so they could be better viewed from the air. "I went through so many brooms," she said in a seminar some time before her death, "rumours circulated that I might be a witch".
It is probably just as well the good lady isn't around today to see the latest official aerial photographs of her precious lines. One of the most famous animal figures, the monkey, was crisscrossed by tyre tracks that have mashed the top of its spiral tail. The fish and spider lines showed similar scars in the 180 photos, many of which were published in local newspapers.
Last year, highway officials had to move a weighing station ten miles north of the zone to stop cargo trucks from cutting across the lines to avoid paying tolls. And last October, the municipality of Nazca was cited for dumping rubbish inside the protected zone.
In the waiting room before our flight on a flimsy-looking five-seater plane to view Reiche's lovingly-swept etchings, a video playing in the corner had quite an unusual theory as to the origins of the lines.
Apparently, the people of Nazca were indeed capable of flying, once they had snorted enough coca-extracted powders, that is. This hallucinogenic or "astral" flight allowed them to plot the enormous desert markings, informed the deadpan voice-over. Indeed.
We had been warned not to eat a breakfast and 30 seconds into the flight it became apparent why. The pilot kindly tilted the plane twice for every drawing so that people sitting at either side could see the lines out their own porthole windows. This allowed us all to spot a truck crossing the sands dangerously close to the spider drawing. There were 13 figures to see in the space of half an hour which, over soluble painkillers afterwards, we deduced was practically a 180 degree tilt a minute.