The Narrows, St. John's
The Narrows, the only entrance to St. John's Harbour, Newfoundland, is a narrow channel between the Southside and Signal hills. It has a least depth of 11 metres and at its narrowest point near Chain Rock is 61 metres wide.
The Narrows has served an important defence of the city of St. John’s from early pirates and settlers in 1655 to World War II. In 1655 vice admiral Christopher Martin erected a fort on the south side to prevent privateers and enemy vessels from entering the port. In 1763 Fort Amherst was built in the same area. In the late 18th century a defensive chain was erected across the narrows from Chain Rock to Pancake Rock which could be raised in the event of enemy ships advancing into the harbour. During World War II a steel mesh was installed to prevent enemy submarines from entering the harbour.