This pair of hatches comes from original upper gate system of the San Marco lock, in the urban part of the Martesana canal. Built between 1457 and 1471, was commissioned by duke Francesco Sforza to connect the river Adda to Milan.
They are among the most significant documents of the “vincian gates” system, that is the complex hydraulic lock system drawn by Leonardo in Milan at the beginning of the sixteenth century: double-leaf angular wooden gates, a little mobile door for governing the inflow and outflow of the water, control hardware from the towpath.
Following the works of covering the Naviglio in 1929-31, the gates were removed and preserved first at the Civic Siloteca Cormio, at the Museum. In 2016 they have been the subject of important investigations into their state of conservation, dating and organic composition. On a structural level, each door is composed of a sturdy bearing frame in ash wood and spruce paneling, fixed through an accurate jointing system. Due to past maintenance interventions, the doors have elements built in different periods between XVI and XVIII century.