The complex of the Spaso-Preobrazhensky, or Savour-Transfiguration, monastery also belongs to Kremlin's Orthodox legacy. The monastery is situated near the Spasskaya Tower. Its construction is believed to have started in 1557. The complex includes the entire cellar of the Spaso-Preobrazhensky Cathedral built in 1595-1601, the Church of St Nicholas Patron of Warriors (Ratnyi), the Brethren's Building and the Catacomb of the Saviour-Transfiguration monastery, constructed in 1596 and located near the altar wall of the cathedral. There is a vaulted stone framework below the present-day ground level, which served as the burial ground of the saints of Kazan.

This monastery was the centre of the missionary activity in the Kazan province and held a cemetery for the most respected and noble citizens of Kazan.