"Remote valley" refers to a location that is far away from civilization, typically a lower-lying area surrounded by mountains or hills. It suggests a place that is secluded, distant, and possibly difficult to access. Full definition
In 1976, filming the movie King Kong in one of the most remote valleys on Kauai seemed like the perfect location to create «Skull Island». (poipubeach.org)
Having said that I saw many Quechua families hiking long (long) distances through remote valleys with huge loads of things like firewood on their backs.... (theprofessionalhobo.com)
The dramatic Dolomites offer long ski runs through remote valleys. (thetravelmagazine.net)