(Reuters) - Squatters have started raising pigs on the site of Peru's Nazca lines - the giant designs best seen from an airplane that were mysteriously etched into the desert more than 1,500 years ago.
The squatters have destroyed a Nazca-era cemetery and the 50 shacks they have built border Nazca figures, said Blanca Alva, a director at Peru's culture ministry.
She said the squatters, the latest in a succession of encroachments over the years into the protected Nazca area, invaded the site during the Easter holidays in April and that Peruvian laws designed to protect the poor and landless have thwarted efforts to remove them.
In Peru, squatters who occupy land for more than a day have the right to a judicial process before eviction, which Alva said can take two to three years.
"The problem is that by then, the site will be destroyed," she said.
She said she counted 14 pig corals in a recent inspection that also revealed broken bits of Nazca ceramics.
The Nazca lines known as geoglyphs, declared a UNESCO world heritage site in 1994, were produced over a period of a thousand years on a 200 square mile (500 square km) stretch of coastal desert.
They include enormous birds, monkeys and other geometric shapes. The culture ministry evicted a separate batch of squatters in January from near a sprawling design known as the Solar Clock, only to face down a new group months later.
The lines are striking reminders of Peru's rich pre-Columbian history, and are considered one of the world's greatest archeological enigmas, as no one knows for sure why they were drawn, so large, and for so long.
"They're very delicate and they've survived to this point for 1500 years," said Ann Peters, an archeologist affiliated with the University of Pennsylvania, who hosted an international symposium on Nazca culture in Peru this week.
Peters said encroachments in the area threaten research by 60 or so archeologists specialized in Nazca.
Ancient Nazcans formed the figures by scraping away the desert's dark iron-oxide pebbles to reveal the white soil underneath, which hardened as unearthed limestone was exposed to morning dew.
"Our population keeps growing," he said. "These are poor people who don't have the money to buy land or a house."
Arias said the culture ministry should do a better job marking the boundaries of protected areas.
The culture ministry's Alva said squatters are the biggest threat to Peru's more than 13,000 archeological and heritage sites, a rich trove of information for scholars around the world.