view of entrance

Castle Hill Historical Background
From 1692 to 1811, Castle Hill played an important role in the defence of Placentia. The strategic importance of Placentia and the struggle for its control was part of the larger Anglo-French rivalry for an empire not just in Atlantic Canada but also in North America as a whole. Placentia was economically and strategically significant because of its position in the fisheries and because it flanked the approaches to what is now eastern Canada.
The French royal colony of Plaisance (modern-day Placentia) was established in 1662 to encourage and support the French fishery and to stop English fishermen from expanding into the south coast of Newfoundland. It was also a base from which to defend the approaches to New France in times of war. Between 1690 and 1710, the defences of Plaisance were greatly strengthened. The first work within the boundaries of present day Castle Hill nhsc – Gaillardin Redoubt – was constructed in 1692. Fort Royal was begun the next year and completed in 1703
A  disply in visitors centreThe town was a base from which several destructive campaigns were waged against the English fishery. The Royal Navy made three unsuccessful attempts to capture Plaisance before implementing a blockade of Placentia Bay to prevent supply ships from getting through. Although the blockade caused occasional hardship and hunger, the settlement survived to the end of the War of Spanish Succession in 1713.
In 1713, by the Treaty of Utrecht, France recognized British sovereignty over Newfoundland and abandoned Plaisance and other south coast settlements. The British occupied the town, which they renamed Placentia. In 1757, British military engineer Richard Dawson was the first to use the name Castle Hill. During the Seven Years War, there was significant military construction in the town itself. The only major construction on Castle Hill was a blockhouse that was built within the walls of Fort Royal.
Placentia was never attacked again, but in 1762 when French forces occupied St. John’s, Governor Thomas Graves took refuge in Placentia. Fort Royal was renamed Castle Graves in his honour. After the dwindling British garrison was withdrawn in 1811, Placentia remained an important fishing port and regional supply centre.
In 1968, following several years of historical research and a major archaeological project, the Historic Sites and Monuments Board of Canada recommended to the Minister responsible for Parks Canada that Castle Hill be designated a national historic site. Castle Hill was acquired by Parks Canada and officially opened in 1968.
(text from: the Management Plan for Castle Hill National Historic Site of Canada.)Placentia from Castle hill