United Kingdom Wooltack Bay

Wooltack Bay actually looks in the other direction, but from this point it easy to look in any direction. It has wide open views of the ocean and over Skomer and Skokholm. High views from the cliffs.
Although I haven't been able to try this yet, there appears to be very little light pollution and I can imagine that this location would be good for astro.

There is such a great variation of possibilities from here that it's difficult to give advice.

There is parking available at the Lockley Lodge Visitor Centre.