There is one piece of historical evidence documented within as well as without The Bible which utterly seals the empty tomb of those that reject Christianity: the first Christians.
After Jesus' crucifixion, the apostles were scared. They had scattered and were in hiding. In their heart of hearts they were defeated as their leader was now dead. They had forgotten His words to them that this was to happen. A very short time later there was a tremendous transformation in them.
They went from cowering fugitives to the bravest, open and forthright individuals who spoke with utmost boldness in regards to why: the literal, physical resurrection of the Lord Jesus Christ.
They were willing to put it all on the line for their testimony. It is this testimony by these eye-witnesses which proves beyond a shadow of a doubt that this, the very core of Christianity is absolutely true.
But, WAIT!
Some may object; many people die for things they believe in all the time from all religions from the cults like those of David Koresh to the Muslims that kill themselves daily. What makes their martyrdom any less valid to those of Christianity?
The difference is that while many would die for what they believe to be true; no one knowingly and willingly dies for what they absolutely KNOW is a lie!
The apostles and the 500+ other eye witnesses had nothing to gain but misery and death. If at any point they were faced with death, all they needed to do was admit that they had made it all up.
They were horribly executed for what THEY THEMSELVES SAW WITH THEIR OWN EYES!
This is a huge difference and a major point that so many skeptics fail to realise and the logic that it necessarily entails is the final nail in their coffin.
This is aside from the fact that there were many enemies of Christ in authority who could and would have ended Christianity before it had begin merely by parading His body in public, the very fact that they didn't was because they couldn't, because He was no longer in the grave.
While this doesn't "prove" the resurrection, it lends incredibly rational support for it. So, those that still fail to accept the Biblical account and believe Jesus Christ as their living Lord and Saviour haven't a leg to stand on. Their God-given choice is on their own heads should they continue to live in denial in spite of this flawless logic.
For further reading on this subject go here.