(CNN) — Wherever you go, the experience is usually the same. You enter a church or a cathedral, and an ecclesiastical hush descends. You admire the architecture, the artworks, the centuries of history and of faith that have stood the test of time.

And then you enter a special chapel or museum, where the holiest of items resides. Behind a glass case stands the stuff of legend: the Holy Grail. Or is it? What makes this cup the Holy Grail – but not another? In Europe alone, there are said to be around 200 cups, each thought to be the Holy Grail – the cup used by Jesus Christ at the Last Supper.

Believers flock to see them and pray over them. But which is the real grail – and does it even exist? One thing’s for certain – the Holy Grail is embedded deep into our collective imagination. The idea of a quest is a constant theme in literature, art and movies, while we routinely refer to what would be our ultimate goals – but usually lie tantalizingly out of sight – as the “holy grail.

” Major medical breakthroughs are often called the “holy grail” for the disease in question. It’s part of pop culture, too. Dan Brown made millions off his interpretation of the Holy Grail in the “Da Vinci Code,” in which he posited that the grail was not in fact an object, but a secret – that Jesus Christ had fathered children with Mary Magdalen.

And who can forget Harrison Ford reaching out for the “cup of a carpenter” in “Indiana Jones and the Last Crusade”? Even.