Lithuanian archaeologists know how to keep a secret - they waited 13 years before revealing they had discovered treasures worth more than $100 million in the Vilnius Cathedral.

The cache, shown this week to President Valdas Adamkus and other top officials, includes hundreds of jewels, gold goblets and church artifacts dating back to the 16th century.Workers came across part of the treasure in 1985, when Lithuania was still part of the Soviet Union, while fitting the cathedral with air conditioning. Archaeologists were then brought in to explore further, and they found the rest.

It was a stunning find, one of the archaeologists, Romualdas Budrys, director of the Lithuanian Museum of Art, recalled Friday.

"We were searching with ultrasound equipment and suddenly the sound changed," he said. "So, we broke one brick wall and were blinded by the shining of gold. I still remember the pale faces of my colleagues."

They informed the Lithuanian Ministry of Culture about the find but vowed not to tell Soviet authorities, fearing it might be confiscated. Withholding such information from the Kremlin was a risky move.

"In those days, our tongues were our greatest enemies. But we managed to keep the secret until safer times," Budrys said.

He did not say why they waited nearly seven years after independence to make the find public or where it had been kept all that time.

Archaeologists believe the treasure was hidden in 1655 when Russian troops stormed Vilnius, which was then part of a Lithuanian-Polish political union.

Lithuanian state authorities said they plan to exhibit the treasure, which Lithuanian experts estimate is worth more than $100 million.