UMs: Lost Artifacts/Civilizations part 4

Back again to another installment of one of my favorite categories of Mysteries, the Lost Civilizations/Artifacts. So throw on the best example of a cover of the famous theme and read on:

Some will say the council of Nicaea was inspired, (which it vary well may have) but there's no arguing that it also didn't bother to try to preserve that which was rejected from being included in today's Bible, and that which is was somewhat arbitrary. So, are there lost gospels that can still be verified? 
https://www.reddit.com/r/UnresolvedMysteries/comments/safxa6/in_the_evening_the_youth_comes_to_him_wearing_a/

Olivier Levasseur was a well educated naval officer turned pirate, who on the day of his public execution, reportedly threw a written cipher into the crowd exclaiming that his treasure could be found with it:
https://www.reddit.com/r/UnresolvedMysteries/comments/n8iujj/legend_tells_of_a_pirate_named_olivier_levasseur/

I believe I have mentioned the famous Amber Room here before, but it's just too interesting to not go over all the theories as to what happened after the Nazis took it:
https://www.reddit.com/r/UnresolvedMysteries/comments/qos6l4/during_wwii_the_nazi_army_looted_the_amber_room/

The Jackson Tennessee Hoard was a buried case of about 500 to 800 gold coins discovered in 1985 by city workers. But no one is still sure how it got there and who done it?
https://www.reddit.com/r/UnresolvedMysteries/comments/jftun6/how_did_a_hoard_of_19th_century_gold_coins_end_up/

The Sandby Borg is't an episode of Star Trek, but rather an Iron Age ringfort on an island of Sweden where archaeologists suspect a massacre happened. However, it appears there was little to no resistance, the bodies as well as valuables remained not looted at the time, and it was immediately inhabited again without the bodies being moved:
https://www.reddit.com/r/UnresolvedMysteries/comments/mdyyel/the_mystery_of_the_sandby_borg_ring_fort_in_sweden/