Work has begun to save one of the holiest shrine in Christendom. It won’t be a simple patch-and-paint job. They are going to repair Jesus’ tomb — with titanium bolts.

The Church of the Holy Sepulcher in Jerusalem is one of the most popular religious sites in the world.

The cavernous basilica, filled with obscure niches, secret Crusader tombs, and hidden chapels and golden icons, marks the site where Catholic and Eastern Orthodox faiths believe that Jesus died, was buried and rose.

Archaeology at the Church of the Holy Sepulcher has been limited, not only by protective clerics but also by centuries of tradition. The site is considered the most sublime in Christendom, a place of pilgrimage, faith, passion and mystery — not digging and probing.

Patriarch Theophilos III, of the Orthodox Church of Jerusalem, told The Washington Post: “There is no doubt that there is some kind of energy. I don’t want to describe it, but some kind of energy that emanates from this place.”

Theophilos said he has reread the historical accounts of his predecessors who saw the ruins of the tomb when it was last exposed in 1810.

Here in the ancient alleys of Jerusalem, two centuries is not a long time. But in 1809, the last time clerics and workers exposed the Holy Rock, Thomas Jefferson was the American president, people didn’t know that germs caused disease and the science of archaeology did not exist.

Theophilos sat perched on a velvet chair in the recesses of the church, surrounded by a dozen members of his retinue, including a pair of bodyguards each sporting a red fez and a long cane to push overeager congregants back.

The previous Crusader-era chapel was destroyed by a catastrophic fire in 1808, the patriarch said.

When the Greeks were rebuilding in 1809, Theophilos said, “Everybody was so excited to see part of what has remained of the original cave that served as the tomb of Christ.

“Now? To be honest, we have the same feelings,” the leader of the Greek church said. “You cannot remain indifferent.”

He smiled but warned his guest: “This is not an archaeological monument. Those stones are not mere stones.”

What is there?

The British archaeologist Martin Biddle, who studied the site in the 1990s, speculated that there could be ancient graffiti left by pilgrims somewhere around the Holy Rock or beneath the floor under the rotunda, perhaps scribbles of “He is risen!”

Or maybe the small, scratched crosses left in the caves of Christians in the first centuries after his death.

Or maybe just cut stone.

Whatever evidence exists, the conservationists won’t know until they get there — and even then, will it prove definitively that this was the tomb of Jesus?

The Greek team has promised to keep the church open to visitors and pilgrims throughout the restoration, meaning its members will be working in the deep of the night, the site lit by their own portable generators and a hundred vigil lamps.

“This is a very challenging environment. Very profound. Yet very exciting,” said Moropoulou, a leader of the Greek team.