Probably more then we could imagine. The Vatican is only one location. But there’s many locations and groups all over the World one could suspect of maintaining secret archives.
Many of the Buddhist groups in Nepal and Tibet for instance are just as old if not older then the Catholic Church. The odds of them having a secret archive perhaps tucked back in an out of the way Temple in an almost forgotten mountain valley are pretty high.
Many of the European Knightly orders are also suspected of maintaining their own secretive archives and records.
The various Royal Houses of Europe also likely have theirs.
As did likely many of the Ancient Groups, and Guilds who dealt in esoteric and borderline heretical knowledge. Such as the Alchemists for instance.
Some of the contents of those rumored libraries particularly in Europe likely were condensed into larger collections as various Cities and Castles were sacked, the balance of power shifted, and families died out.
Probably more then we could imagine. The Vatican is only one location. But there’s many locations and groups all over the World one could suspect of maintaining secret archives.
Many of the Buddhist groups in Nepal and Tibet for instance are just as old if not older then the Catholic Church. The odds of them having a secret archive perhaps tucked back in an out of the way Temple in an almost forgotten mountain valley are pretty high.
Many of the European Knightly orders are also suspected of maintaining their own secretive archives and records.
The various Royal Houses of Europe also likely have theirs.
As did likely many of the Ancient Groups, and Guilds who dealt in esoteric and borderline heretical knowledge. Such as the Alchemists for instance.
Some of the contents of those rumored libraries particularly in Europe likely were condensed into larger collections as various Cities and Castles were sacked, the balance of power shifted, and families died out.