In the 16th and 17th centuries, the three circular defenses were built: Kitay-gorod (Китай-город), the White City (Белый город) and the Earthen City (Земляной город).
Three square gates existed on the eastern side of the Kremlin wall, which in the 17th century, were known as: Konstantino-Eleninsky, Spassky, Nikolsky (owing their names to the icons of Constantine and Helen, the Savior and St. Nicholas which hung over them).