Guarding the entrance to St. John's harbour is Fort Amherst. First established in the 1770s and named for William Amherst who recaptured the city from the French in the 1760s, Fort Amherst was an important military site for most of its existence. It was not until the 1810s, when pressure from the fishing and commercial industries prompted the creation of a stone tower, would the province see its very first lighthouse, built on the site of Fort Amherst.

By 1834 repairs were made to the site and an improved light was exhibited. Even then however, a more effective harbour light was deemed necessary and in 1852 a completely new structure was to be built. It would be this lighthouse that soldiered on throughout both World Wars, and into confederation. In 1951, the old tower and adjacent structure were torn down, and replaced by the 25 foot tall wooden tower which stands today. The current structure exhibits a flashing white light every 15 seconds, at a focal height of 40 metres, out to a range of 17 nautical miles.