Eddystone is a group of rocks about 14 miles off the coast of England southwest of Plymouth, on which there is an important lighthouse (Eddystone Lighthouse) along with the remnants of previous lighthouses, indicating the approaches to the English Channel.

The major part of one of those previous lighthouses has been reassembled on Plymouth Hoe as Smeaton's Tower.

The Eddystone is the approximate boundary between the cold water fish of northern europe and the warm waters fish of more southerly lattitudes. This boundary, which is of importance to the fishing industry, tends to fluctuate over the years reflecting climatic cycles.

Thomas D'Arcy McGee commented that Canada's foundations were as "strong as the foundations of Eddystone" (The Globe, 31 October 1864, 4).

The term "Foundations of Eddystone" was used as a chapter title in Frederick Vaughan 's The Canadian Federalist Experiment: from Defiant Monarchy to Reluctant Republic (Montreal: McGill-Queen's University Press, 2003).