The Cerchia dei Navigli was the floodable defensive moat of the medieval walls of Milan, with its southeastern part transformed into a Naviglio, or navigable canal. For this reason, it was also known as the Naviglio Interno, Fossa Interna, or Cerchia Interna. Measuring 6.5 km in length and 9 m in width in its navigable section, it was completely filled in accordance with the Piano Beruto, Milan's first urban plan, starting on 16 March 1929, with works concluding the following year. The Cerchia dei Navigli, as a whole, was a ring of water encircling the medieval historic centre of Milan, hence its name.

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