The Peterborough Lift Lock lifts ships 19.8 metres (max 30.5 m long, max 7.3 m wide, max 99,000 kg). The 386 km waterway (with 45 locks and 39 swing bridges and 20 km of man-made channels), is a Canadian National Historic Site and takes 5-7 days to traverse. Construction begain in 1833 and by 1920 a ship could travel from Lake Ontario to Lake Huron. At the time it was built, it was the largest un-reinforced concrete structure on Earth.