The Mirror Hall of Persepolis is another name for the Thacher Palace; a palace built by order of Darius the Great, and due to its use of polished and shiny gray stones, it reflected the image of people, and therefore it is called the "Mirror House." Thacher means "winter house" and is one of the first palaces built in Persepolis.And numerous motifs and inscriptions of Achaemenid kings are engraved on the walls of its staircase.