Fresh air and lovely surroundings await you at Vitkov Hill. If you need some time out from the asphalt jungle, you'll find some respite here.
You're spoiled for sightseeing choice in Prague 3. Vitkov Hill is a great place to kick off here, but there are lots of other worthwhile spots to consider. Charles Bridge, Old Town Square, and Prague Castle are near the recreation and green space and and will cap off your day nicely.