English: A widow's watch tower, also called a widow's walk, on top of a Victorian-era house on Douglas Avenue in Saint John, New Brunswick, Canada. Several Victorian-era houses in Saint John and other North Atlantic port cities have these towers, where wives and other family members of ship captains could watch the horizon for the first glimpse of the returning ship. In warmer climates they include an exterior walkway with a railing. In Canada, they are usually completely enclosed.
N.B.: This is rather a belvedere (rooftop pavilion) than a widows' walk (railed unroofed platform) [1]