Unearthed by archaeological excavations at different times at the shore of Lake Erie and the bank of the Niagara River, 1.2 million artifacts dating to 4000 BC begin to tell the story of civilization. Documentation of this rich heritage resource began in 1887 when Canada's first full-time archaeologist, David Boyle, noted interesting finds. An ossuary (mass grave) was discovered in the 1960s beneath the streets and buildings, and since then, work has continued. Most notable are finds related to construction at the Peace Bridge in the 1990s.