The original mouth of the Toronto harbour pointed west, near the present day Western Gap. Fort York, on the north shore of the bay, near the mouth of Garrison Creek, guarded the harbour's mouth. It was briefly captured by American forces during the War of 1812. From 1908 to 1911 the area was rebuilt by the federal government. A new western channel was dug 1,300 feet (400 m) to the south of the existing one. The existing channel could not be dredged to a lower depth as it was solid rock.
This entrance to the Toronto Harbour from the Humber Bay is extremely busy and narrow and is a great place to watch boats and aircraft in the summer months.
Most commercial traffic now uses the main eastern gap for entry to the inner harbour. Toronto Western Gap itself is a narrow channel with a minimum width of 300 feet and minimum depth of 27 feet. The sides is are concrete with no place to pause or tie up. A passenger ferry - the "Marylin Bell" crosses the western Gap every 15 minutes to the island airport.
