DopamineNL: As the last cacher only found the empty cache-location it seems the new nano disappeared completely empty...
That can't be good.
It's been fun, but the puzzle is too hard and the tree that held the cache is breaking down. Time to archive.
The puzzle consisted of coordinates (written in Iranian numericals) that indicated "tourist" attractions or landmarks in and around Tehran. The numbers of the city's districts (like Paris' arrondissements) where these points are gave the final location.