The canals in Venice vary in depth depending on their size and location. Most of the smaller canals have a depth of about 1.5 to 2 meters (5 to 6.5 feet). The Grand Canal, which is Venice's largest and most important waterway, has an average depth of approximately 5 meters (16 feet). Another large canal, the Canale della Giudecca, is deeper, with depths ranging from about 12 to 17 meters (39 to 56 feet). Outside the historical city but within the lagoon, some areas reach depths of over 20 meters (66 feet), and the deepest part of the Venetian Lagoon, the Fossa delle Ceppe, can be around 50 meters (164 feet) deep. The depth of the canals also fluctuates with the tides, typically varying by 0.5 to 1 meter or more throughout the day.