Most today think of the crucifixion as taking place up on a rocky hill, but Trestrail told "20/20's" Elizabeth Vargas that in Jesus' day people were actually executed in a desolate valley that was once a quarry. He showed Vargas a cliff above what is now a municipal bus station that he believes gave the place its haunting name.
In the rock you could make out shapes that could look something like a skull, eye sockets and a nose, he said. But Trestrail later admitted the cliff didn't look much like a skull any longer. According to earlier accounts, Trestrail says, it did. But the rock has since eroded.
Still, the majority of Christians believe the site of the crucifixion and the tomb is in the Church of the Holy Sepulchre.
The church was built in the year 325 by Constantine, the first Christian ruler of the Roman Empire. It is said that local Christians led Constantine's mother to the site when she asked to see Jesus' tomb. When Constantine's men dug below the temple, it is said they found a tomb there.
Inside the church, a simple rock tomb has been housed in an 18th-century shrine. Murphy-O'Connor thinks Jesus' body was laid somewhere along an eerie tunnel lined with narrow shafts for the dead.
Scholars say there's little dispute about whether the tomb was empty. Even those who doubted the Resurrection, Baumgarten says, never doubted that the tomb was empty.
The only point of dispute is: Why was it empty?
"Christians said the tomb was empty because Jesus had been resurrected and Jews said that the tomb was empty because the disciples stole the body, and they did that as kind of a plot to fool people," said Baumgarten.
Strobel said the disciples had no motive to take the body. "The disciples weren't about to steal the body and then willingly die for a lie. The Romans weren't about to steal it. They wanted Jesus dead. So I think that idea is easily dismantled," he said.
Indeed, if the body had been stolen, there may have been some account of its removal through the centuries. But there are no stories of individuals or groups claiming to have removed the body.
"If the body had been discovered, there would be no Christian church today. It would have died out as a little sect in the Judean wilderness probably and everybody would have laughed about a crucified criminal being the son of God, come on," said Paul Meier of Western Michigan University.
"It's discovered that the body is not there. And that's the point of major importance. That's where it all begins," said Schwartz.
But even if there is pretty good historical reason to believe there was an empty tomb, does this mean that Jesus was resurrected from the dead?
The Bible says that starting on Easter Sunday -- and for a brief period afterward -- the resurrected Jesus of Nazareth actually appeared to his followers.
In one story, he appears to Mary Magdalene in the garden right beside his tomb, just after she has discovered his grave is empty.
"Distraught her beloved master's body is gone and she then sees him and thinks it's the gardener and Jesus just turns to her and says, 'Mary.' And she recognizes his voice and falls at his feet in worship. I think this is one of the tenderest moments in the Resurrection appearance stories," said Craig.