Conca dell'Incoronata, Navigation lock in Via San Marco, Milan, Italy.

Conca dell'Incoronata is a navigation lock at the terminus of the Naviglio Martesana canal in Milan, featuring stone construction and original gates. The structure allowed boats to move between different water levels as they entered the city.

The Naviglio della Martesana was completed in 1463, and the height difference with the Cerchia dei Navigli required a lock. Leonardo da Vinci studied the problem in 1482, leaving design sketches in the Codex Atlanticus, but the lock was built only in 1496 under Ludovico il Moro, directed by engineers Giuliano Guasconi and Bartolomeo della Valle with Leonardo as consultant. It lost its function when the canal ring was buried between 1929 and 1930.

The lock is named after the nearby church of Santa Maria Incoronata and the Ponte delle Gabelle, the first river gateway into Milan, where barges paid a duty (gabella) on their cargo. The name thus records both the church and the toll point that once stood beside the canal.

The site is located on Via San Marco in the city center and remains open throughout the day without entrance fees. It connects easily to nearby neighborhoods and is accessible on foot from major transit points.

The 1967 monument listing cites the site as the last surviving stretch of the urban Naviglio Martesana, with the last old bridge over the canal, the last lock chamber and a small sentry box (garitta) from the navigation works. The moorings where goods were unloaded have disappeared.