St. John's tomb

I really had to restrain myself from titling this post, Who's buried in St. John's tomb? Because, as it turns out, the answer is “no one.”

Unlike Mary, there is historical evidence for John's presence in Esphesus, and most traditions have him dying of old age there, the only Apostle who wasn't martyred. But during the reign of Constantine, only a few hundred years after John is believed to have died, for some reason the tomb was opened and was found to contain no bones. This has been explained as proof that John, like Mary, was assumed into heaven upon death.

I think it is more likely that the traditional tomb was just built in the vicinity of where John was known to have been buried—that's certainly common enough in history.