The find
In 1968, builders were clearing ground at Giv'at ha-Mivtar, a neighbourhood in the north of Jerusalem. They broke into a Jewish family tomb from the 1st century, cut into the rock.
Inside were stone bone boxes, called ossuaries. In that time, a body was laid in the tomb, and a year later the family gathered the bones into a box. One box was inscribed with a name: Yehohanan, son of Hagqol.
The heel
Among his bones was the right heel. Through it, from the side, was an iron nail.
The nail had been driven through the heel into the upright of a cross. Its tip struck a knot in the wood and bent. When the body was taken down, the nail couldn't be pulled out. So it was buried with him, still in the bone, along with traces of the wood.
Why it matters
Before 1968, crucifixion was known from Roman writers and from the Gospels, but nobody had ever found a crucified man.
Rome crucified thousands of people. Almost no trace survives, because the nails were usually pulled out and reused, and the bodies were often left to the birds. This one survived by accident, because of one bent nail.
It shows that crucifixion in Jerusalem in Jesus' time was done the way the Gospels describe: iron nails, driven through the body, into wood.
Jesus himself showed his followers the marks:
"See my hands and my feet, that it is I myself: feel, and see: for a spirit hath not flesh and bones, as you see me to have. And when he had said this, he shewed them his hands and his feet."
Luke 24:39 to 40
A thousand years earlier, David had written it: "They have dug my hands and feet" (Psalm 21:17).
Buried in a tomb
There's a second point, just as important.
Some critics have claimed that crucified men were never given a proper burial, so the Gospel story of Jesus being laid in a rock tomb can't be true.
Yehohanan was crucified by the Romans, taken down, and laid in his family's rock-cut tomb in Jerusalem, his bones later placed in a named ossuary. A crucified man, given a proper Jewish burial.
That's exactly what the Gospels say happened to Jesus, when Joseph of Arimathea asked Pilate for the body and laid it in a new tomb cut in the rock (John 19:38 to 42).
Why this is a big deal
Out of all the thousands Rome crucified, one heel bone survived, with the nail still in it. It confirms the method, the place and the time.
And it confirms that a man crucified in Jerusalem could be taken down and buried in a rock tomb, just as the Gospels say Jesus was.