#27 Two of Argentina’s most interesting unsolved mysteries are the Jesuit Treasure and the secret tunnel networks found in several cities.
The Jesuit Treasure comes from the Misiones region: when the Jesuits were expelled in 1767, legend says they hid a massive amount of gold, silver, and documents in underground chambers. Many expeditions have tried to find it, but no solid evidence has ever appeared, so it remains a mix of history and myth.
Another long-running mystery involves the underground tunnels. Buenos Aires has colonial tunnels in San Telmo and Montserrat whose real purpose is still debated—smuggling, drainage, hidden storage, or something else. The strange part is that many sections don’t match the official city plans of the era.
And it’s not just Buenos Aires: Córdoba, Salta, Mendoza, and several older cities also have undocumented tunnels from colonial times that no one fully understands. Some are sealed, some reappear during construction, and almost none have proper historical records explaining why they were built.
All of this leaves Argentina with a surprising amount of underground mysteries still unsolved.
