Hi Bruce
Bang on. I was in St John's for a few days recently and had a chance to poke around below the Fort Amherst lighthouse. It's on the other side of the harbour entrance from Signal Hill and Cabot Tower.
There are two guns below in the remains of concrete fortressing below the level of the lighthouse. 4.7in Mk II.
And I crossed The Crow's Nest off my bucket list.
regards
Darrell