Rennes-le-Château

The account

A hilltop village, a renovation, and then money: towers, gardens, banquets, on a curate's salary. Parchments in a pillar, Visigoth gold, blackmail, the Templars, every theory has its dig site. The village finally banned shovels. The mystery never noticed.

Leads, where the trail points now

• The mystery is the source of Father Berenger Sauniere's sudden 1890s wealth; the documentary trail is his account books, his building works like the Tour Magdala, and diocese records, not buried gold.
• The coded parchments made famous later were exposed as 1960s forgeries tied to Pierre Plantard's Priory of Sion hoax; treat the Holy-Grail-era clues as fabricated.
• The most credible explanation is trafficking in masses, selling more than he could perform, which is mundane but documented. A literal treasure remains unproven.
• The church and village are private and heavily picked over; this is a documentary puzzle, not a dig.