York Redoubt, located on a bluff overlooking the entrance to Halifax Harbor and across from the fortifications on McNabs played a key role in the defence of the harbor and city in the 19th and 20th centuries. The fortification commenced as a blockhouse in the 1790s during the British-French conflict as part of the Halifax Defence Complex. Several gun emplacements including Sandwich Point and Connaught Batteries were established near the redoubt around the turn of the 20th Century.
During the Second World War York Redoubt served as a command post for harbor defence. With German U-boats operating off the coast a steel anti-submarine net ran below the redoubt across the harbor to McNabs Island to prevent enemy subs from entering the harbor. A guarded swing gate in the centre allowed naval and merchant ships to enter and leave the harbor. Today, the sprawling redoubt with a panoramic view of the harbor includes gun emplacements, fire command post, main magazine, tunnels, searchlight towers and picnic tables.