I don't know the name of the park area this photo was taken from, but it's just south of the Lennon Wall, and Museum Kampa rests here. I'll toss in a link for google street view of the location and angle if anyone would like to visit.
This park was very chill. People lazily sitting around, enjoying the night air with a loved one or a loved beer. If you're spooked easily however, be careful of the shadows. The moonlight can really mess with your head the way it dances through the trees to seeminly animate some of the creepier looking statues in Prague, including the faceless babies.