Signal Hill is strategically located high above St. John’s  overlooking the ocean and the mouth of the narrow channel that leads into the city harbor.  It’s long been used for defense, observation, and has been used for signaling since 1704. There is a lot of history to this hill which you can look up if interested.  For instance, the hill has been captured by the French four times.  Cabot Tower on Signal Hill was constructed in 1897. 
Half way up the very steep hill there is a parking lot but we went to the top and managed to park even though there is no RV parking.  The views are 360 degrees and we had a clear day to see all the way to Cape Spear, the most easterly point in North America; as well as the city, the lighthouse at the entrance to the harbor, and far out into the ocean.
                                     Cabot Tower


                The point in the upper right is Cape Spear
      The visitor center is in the house with the peaked roof.  View of the city was not good because of glare from the sun.
        Signal Hill is also a good vantage point for spotting whales