A Hotel in the Skies
For that top-of-the-world feeling, it would be hard to beat Pic du Midi. Sitting on top of the French Pyrenees, it's only accessible by cable car from the ski resort of Le Tourmalet. But when you get there, it's worth the effort. There's an observatory, an astrological discovery center, a restaurant, and the chance to spend the night.
The time to get there is late afternoon, so you have enough time to take in the breathtaking panorama before sundown. Then you can sit and observe the sun setting. After darkness has descended, you can attend an astronomy workshop and learn about the constellations.
If you're very lucky (and plan in advance), you can have dinner on the mountain, watch the sun set, and stay the night. Then, next morning, you'll wake up for sunrise and breakfast.
Space and dates are extremely limited, but there is availability through the winter, starting at 199 € per person.