[weinzierl]

I read the Wikipedia article about it and the sad thing is that the majority of the Yongle Encyclopedia seem to have been destroyed only in quite recent times.

[knolax]

> but 90 percent of the 1567 manuscript survived until the Second Opium War in the Qing dynasty. In 1860, the Anglo-French invasion of Beijing resulted in extensive burning and looting of the city,[16] with the British and French soldiers taking large portions of the manuscript as souvenirs.

Preservation is easy if you don't get invaded.

[asdff]

It's easy if you anticipate these things. Who put the dead sea scrolls in that cave in the middle of nowhere? Not someone who went in and forgot their scroll one day. Someone who had the foresight that this would be a safe space in the face of who knows what future threat. And it payed off.

[zaarn]

I doubt it was that intentional. I would wager that "someone forgot about it" is the more likely explanation.