By Hannah Hennessy
BBC correspondent in Peru
They don't look much from the ground. But these are the Nasca Lines: one of Peru's top tourist attractions.
The many tourists to the area are proving a blessing and a curse
These giant figures that are etched in the desert are so large they can only fully be appreciated from the sky.
Every year around 80,000 people fly over them, marvelling at images like the monkey with its curly tail or the delicately-carved hummingbird.
Nobody knows exactly why the Nasca people carved hundreds of lines and dozens of figures over 1,000 years ago, but there has been much speculation.
German mathematician Maria Reich spent half a century protecting the site, which she believed was a giant astronomical calendar.
One of the more outlandish theories suggests the lines were meant as a landing strip for alien spacecraft.
From the air, their fragility is obvious.
Dried-out ditches skirt some of the figures, where past rains have forced paths through the desert.
Alberto Urbano is the only state-employed archaeologist working at the Nasca Lines. Standing by a sprawling, putrid rubbish tip, he said nature wasn't the only threat.
Theories abound as to the significance of the carvings
"Another of the big problems is the dumping of litter in the Nasca Lines.
"In this case, we're just three hundred metres away from two beautiful trapezoid figures.
"Another problem is the pillaging of this World Heritage Site by grave diggers, people who loot and sell our cultural heritage.
"And all this does is damage the image for tourism at the Nasca Lines," he said sadly, swatting a cloud of flies away from his eyes and squinting in the hot desert sun.
A handful of guards who remained after Maria Reich died six years ago help protect the Nasca Lines by charging tourists a tiny sum of money to climb a metal observation tower.
But with no adequate transport or radio communication, their job is difficult during the day and almost impossible at night.
Mr Urbano says when darkness falls tourist buses sometimes dump litter, while locals frequently traipse or drive across the fragile area in search of gold in the nearby mountains.
Vehicles used to cut across the lines to avoid paying a toll on the Pan-American highway, which itself slices through the Nasca Lines.
Nasca mayor Daniel Mantilla says he worries about the lines, but like many local officials he has found himself blocked by Peru's underfunded and overstretched culture institute.
He says he was forced to dump litter inside the protected zone because the culture institute failed to approve another site.
"If we don't unite, the situation is going to go from bad to worse and that's what the culture institute and the tourism ministry need to understand.
"They need to unite around the local government, but they prefer to turn against us," he said during an interview in his office in the town of Nasca, around 20km from the lines.
There are calls for the authorities to work together to prevent damage
While there doesn't seem to be any immediate threat of them disappearing, the potential damage to the Nasca Lines is staggering.
These are some of Peru's most precious jewels.
Nobody knows for sure why they were made, but everyone seems to agree something needs to be done now to protect these relics of the past for future generations.
As the sun set over the desert, the last tourists came down from the tower where they had their photos taken with the lines behind them.
Another day over, another busload leaves. But if they came back, what would they find?
For more than 1,000 years, this site has survived.
The hope must be that it will survive another 1,000.