The Finding of the Grail?

"It is true that by the 16th century there were about 20 cups that claimed the honor of being the authentic cup used by Jesus at the Last Supper. But today none of these are considered authentic -- with the exception of the Holy Chalice of Valencia and the silver cup of Antioch." -- Colorado Scholar Janice Bennett

With thanks to seraphimsigrist

Google turns up a reference to an earlier work by a Spanish historian, and even a photograph.

This is perhaps really the Grail as a relic of the Last Supper; the Grail of myth and literature is another matter entirely.