Quiet Zone: 715

A passing truck is seen through the window of a phone booth in Head Waters, Va., inside the National Radio Quiet Zone. A 2013 Pew Internet poll reported that 91% of Americans have a cell phone. The National Radio Quiet Zone, where pay phones are easier to find than a cell phone signal, may be the last holdout in the continued growth of wireless technology.

A passing truck is seen through the window of a phone booth in Head Waters, Va., inside the National Radio Quiet Zone. A 2013 Pew Internet poll reported that 91% of Americans have a cell phone. The National Radio Quiet Zone, where pay phones are easier to find than a cell phone signal, may be the last holdout in the continued growth of wireless technology.