Goran Olsen was out on a hike in Haukeli, not far from Oslo, Norway, when he spotted something poking out from under a rock.
It turned out to be an eighth century iron sword - and one in such good condition that it could be restored to a fighting edge. Well, if you replaced the hilt, which is missing - probably it was mostly leather or wood.
Amazingly, the sword had been sitting there next to a fairly popular hiking trail for 1200 years. Archaeologists aren't sure how it got there, but suspect it was either part of a burial or somehow lost by a traveler, perhaps after an ambush.
The surprise is how long it stayed there without being found.