The back of beyond
Definition 1 of 1
Pro Tip 1/3Geographic Isolation
Used to describe places very far from cities or towns, often without many people or conveniences. 
After retiring, Aunt May decided to settle in the back of beyond, surrounded by nature.
Pro Tip 2/3Emphasizing Distance
Expresses that something is an extremely long way away, often used to exaggerate for effect. 
Their new house is in the back of beyond; it took us hours to get there!
Pro Tip 3/3Difficult Access
Can imply that the location is not only remote but also difficult to reach or travel to. 
We'll need a four-wheel drive to reach the cabin; it's in the back of beyond.