From 1508 to 1516, the Italian architect Aloisio the New arranged for the construction of a moat in front of the Eastern wall, which would connect the Moskva and Neglinnaya and be filled in with water from Neglinnaya. This moat, known as the Alevizov moat having a length of and width of , as well as a depth of 9.5–13 m was lined with limestone and, in 1533, fenced on both sides with low, -thick cogged brick walls. Three square gates existed on this side of the wall, which in the 17th century, were known as: Konstantino-Eleninsky, Spassky, Nikolsky (owing their names to the icons of Constantine and Helen, as well as Christ the Savior and St. Nicholas which hung over them). The last two are directly opposite Red Square, while the Konstantino-Elenensky gate was located behind Saint Basil's Cathedral. In the early 19th century, the Arch of Konstantino-Elenensky gate was paved with bricks, but the Spassky Gate was the main front gate of the Kremlin and used for royal entrances. From this gate, wooden and (following the 17th century improvements) stone bridges stretched across the moat. Books were sold on this bridge and stone platforms were built nearby for guns – "raskats". The Tsar Cannon was located on the platform of the Lobnoye mesto.