DAMASCUS, Syria -- In five years of Syrian civil war, 320,000 have been killed. But another cost has been the lost of irreplaceable history, the inheritance of all humanity. Inside Syria, we met the heroes in that fight.
The music filled the ancient Roman amphitheater, that only three months ago was under ISIS control.
It -- like most of the ruins -- only survived that occupation by luck.
But a trove of Palmyra's smaller treasures were saved by dedicated archaeologists -- Syria's very own Monument men and women, led by Chief of Antiquities Maamoun Abdulkarim.
His mission is to protect Syria's heritage from all sides in the civil war.
We met him among the empty display cases of the Damascus Archaeological Museum.
Right at the start of the fighting, Abdulkarim emptied and closed all of Syria's antiquities museums.
As for the priceless exhibits, some 300,000 objects, he and a very few trusted colleagues, hid them.
But he won't tell us where.
"No never, we are just a small group," he said.
But he did agree to show us photos of the crates in their hiding place.
Maamoun's greatest triumph came in Palmyra. His team managed to evacuate 99 percent of its museum artifacts to safety in Damascus, just as ISIS rolled into town.
They destroyed several important buildings, and laced the site with explosives which had to be carefully detonated.
Syria's civil war has kept its treasures off limits for more than five years.
But Maamoun is quietly planning for peace -- eventually -- and the day concerts in the amphitheater are not just for the benefit of soldiers, but once again open to the world.