Planning A Stargazing Trip: The Bortle Scale is the standard tool for rating night-sky darkness and is useful for travelers deciding where to go. It runs from Class 1 (the darkest possible skies on Earth) to Class 9 (inner-city light pollution). Most flagship Gold Tier International Dark Sky Parks measure Bortle 1 or 2 where the Milky Way is bright enough to cast a faint shadow and the zodiacal light is visible to the naked eye. A few practical tips apply across destinations. Plan visits around the new moon since even a quarter moon washes out faint celestial detail. Allow 30 minutes for your eyes to adjust after stepping out of any lit area. Bring a red-filter flashlight rather than a white one to preserve night vision. Summer offers the brightest views of the galactic core but winter brings longer nights and clearer dry air in desert regions. Check the park's website ahead of time for ranger-led programs star parties and special astronomical events https://www.worldatlas.com/places/dark-sky-parks-in-the-united-states.html