"Watch your step," goes a joke by archaeologists in Macedonia, "or you might crack an ancient pot."

It could happen: Tiny Macedonia — which is slightly larger than Belgium but with a population of 2 million — has some 6,000 registered archaeological sites.

Experts warn that since the country gained independence from Yugoslavia 16 years ago, its ancient heritage has become increasingly vulnerable to looters who use sophisticated navigation and excavating equipment, leaving few sites unpillaged.

There is little to stop them.

"This is nothing but an open invitation for illegal diggers to come here looking for buried treasure," said 72-year-old Taip Tahiri, a retired teacher from the village of Dedeli, near Lake Dojran, about 180 kilometers (112 miles) south of the capital Skopje. His family home stands next to a rich Iron Age site with 98 excavated tombs.

"This site has been explored a lot ... but groups of illegal diggers are still active in the area. Many of them made a fortune selling famous Macedonian bronzes to Greeks and other foreign buyers."

Irena Kolistrkoska, head of Macedonia's archaeologists' association, warned each year that scores of local and foreign diggers uncover priceless remnants from the Iron Age, as well as Greek, Thracian, Roman and Byzantine artifacts.

"There are two main reasons Macedonia is failing to seriously protect its cultural treasure: A lack of a strategy at a national level and the absence of credible experts in the field," Kolistrkoska said.

Pasko Kuzman, director of the National Directorate for Protection of the Cultural Heritage, said Iron Age archaeological sites in southeastern Macedonia have been extensively looted.

Police, he said, are already overstretched fighting organized crime, adding that fees offered by corrupt art collectors only encourage illegal excavations.

Macedonia, a landlocked nation in southeastern Europe, has a rich and storied past.

The country is part of the broader Macedonia region that includes parts of Greece and Bulgaria that became a major power in the ancient world under Phillip II of Macedon, and his son Alexander the Great. Alexander was one of the most successful military commanders in history, who built a vast empire that stretched to India before his death in 323 B.C.

Modern Macedonia's claim to the region's ancient heritage has infuriated neighbor Greece, which refuses to recognize the former Yugoslav republic by its official name, and is still seeking arbitration of the dispute at the United Nations.

Macedonia's south, on major east-west trading routes, was successively dominated by different civilizations — ancient Macedonian, Roman, Byzantine and Ottoman.

"Macedonian bronze is trendy. It is world-famous because of the style and it can fetch very high prices on the black market," Kolistrkoska said.

"Even the smallest piece can be sold for €1,000 (US$1,350)."

East of Dedeli lies Isar-Marvinci, where villagers are usually on hand to guide visitors up to a hillside to hunt for ancient fragments.

"You can easily find Roman coins or ceramics. Just look a little carefully. Every stone here is thousands of years old," said a villager, who refused to give his name or even his initials, fearing reprisals from other guides.

Fifteen other local men have been arrested for illegal excavation and trading in artifacts.

"As locals, we can find artifacts easily. But the state is not paying for them. We are jobless and foreigners are often around with money," the man said.

Kuzman said that during excavations at Isar-Marvinci between 1995 and 2003, an estimated 2,500 artifacts were stolen.

"No one knows how many important national treasures have been smuggled out of the country, but it's clear the police don't yet have the means to stop it," he said.

While illegal digs are impossible to stop, Kuzman takes a long-term view and argues much of Macedonia's looted treasure can still eventually be tracked down abroad and returned.

"Every inch of this soil is so rich that many discoveries are still awaiting us," he said. "One of my dreams ... is to bring back to Macedonia a bronze bowl with a beautiful relief, which was recently traced to New York."