This is a fine illustration of how light pollution affects what the night sky looks like to the naked eye under different light pollution levels.
Dark Sky Park Møn is on a Bortle scale of 2, which is the second column from the right.
The Bortle Scale is a simple and subjective way of expressing how dark the sky is, by looking for the faintest stars you can see. The ranking on the Bortle Scale depends on the eyesight of the viewer.
We generally use the more objective measurement of the brightness of the sky made by electronic devices (Sky Quality Meters), which is called "MPSAS", or Magnitudes Per Square Arc Second.