The title is clickbait. It makes it sound like someone hiking in a ravine just happened to stumble upon these paintings. In actuality, the guy just felt guilty,

The title is clickbait. It makes it sound like someone hiking in a ravine just happened to stumble upon these paintings. In actuality, the guy just felt guilty, so he confessed and gave them back. The subtitle says it all: > Ending a long-running mystery, a construction worker guided the police to the hiding place after admitting he had taken the works in a daring one-man raid on the National Gallery in Athens in 2012.