The Santo Caliz of Valencia has an interesting history, the cup appears to date from the first century, and is possibly of Jewish origin.
The legend says it was brought to Rome by St Peter and sent to Valencia for safety by Saint Lawrence, a native of that city.
It is important to be skeptical about relics, but this chalice has a richly documented history that reaches into the first millenium.
Research into the shroud, the titulus of the Cross, the house of St Peter in Capernium, indicate that we can be too skeptical.
A conference on the Santo Caliz has just ended in Valencia.