We arrive on an early-morning flight into Frankfurt later this week. I'm looking for ways to spend the early morning before meeting other members of our group in Frankfurt.
I've heard that the Prinz-Georg-Garten in Darmstadt opens at 7 am and the Rosenhohe opens at 8 am. Are these worthwhile, especially for two people just trying to stay awake by doing something interesting? (I'm from a large city with its own botanic gardens.)