Here's a great example of how the most unexpected things can turn up in the unlikliest places.
http://www.bbc.com/news/world-australia-36219991
John Squire was a British army engineer who was involved at the siege of Badajoz in the Peninsular War. Like all the best army officers of the time, he was a gentleman scholar. He personally knew Wellington, traveled all over the place, and kept a fascinating journal.
Which has turned up in a second hand bookstore in Hobart, Tasmania; about as far from Badajoz as you can get and still be on the same planet. My family and I were there just last year. I must have walked within twenty meters of that journal and never knew.