Although almost all ancient sources relating to crucifixion are literary, the 1968 archeological discovery just northeast of Jerusalem of the body of a crucified man dated to the 1st century provided good confirmatory evidence that crucifixions occurred during the Roman period roughly according to the manner in which the crucifixion of Jesus is described in the gospels. The crucified man was identified as Yehohanan ben Hagkol and probably died about 70 AD, around the time of the Jewish revolt against Rome. The analyses at the Hadassah Medical School estimated that he died in his late 20s. Another relevant archaeological find, which also dates to the 1st century AD, is an unidentified heel bone with a spike discovered in a Jerusalem gravesite, now held by the Israel Antiquities Authority and displayed in the Israel Museum.
What did the Romans keep as a deterrent to others who would revolt? (If the question is unanswerable, say "unanswerable")
unanswerable