Most light pollution is scattered in the lower 6000 ft of the atmosphere (one mile) so you don't need to get terribly far from a city to get "out from under" the scatter. I live 30 miles (over water) from a city of 1.5 million. In my area, star visibility is limited by atmospheric conditions, not light pollution. Under good conditions, the Milky Way is visible in detail.
Because light pollution is low altitude, getting a mountain between you and the pollution source is very effective. We have a narrow fiord nearby with 3000ft mountains. The sky is absolutely spectacular, like the best photographs.
Anywhere on the ocean is great, too. Once you are 20 miles offshore, stars are visible right down to a hard cut-off at the horizon