If you don't already know the state of the night sky, https://darksitefinder.com/ is a great resource.

(If you love the stars, it'll also leave you depressed. There are very few locations left where it's pitch dark at night)

Personally, I’ve been using cleardarksky.com: https://www.cleardarksky.com/csk/

Once you dial in a local observatory, you’ll enjoy hour-by-hour visibility forecasts. It’s been invaluable for my unassisted-eye stargazing activities!

Oh, sure, but that's next-level nerdery above "I just want to find a dark site" :)

It's also invaluable for any assisted star gazing. Turns out driving out 4 hours into the middle of nowhere only to be stuck in the clouds is just not that fun, with or without telescopes. Ask me how I know ;)

non-sarcastically, the night sky in Spain and Portugal must be absolutely stunning right now

Sadly their emergency services may be exasperated with urban citizens who have sighted some sort of malicious UAP, because nobody remembers what the Milky Way looks like in 2025.