There's a lovely open space just before you go into the grounds of Prague Castle and in that space there's a wall that overlooks the city. It's such a beautiful vantage point and you can see red rooftops and spires stretching out into the endless distance.
You can see a little ariel hovering above the cityscape in the left of this picture. It looks like a big television mast. In reality though, our tour guide told us that the same mast had been used to block communications coming into the city during the Russion occupation.