The “Unbreakable (or “Indestructible”) Wall” Icon of the Most Holy Theotokos is commemorated on the Sunday of All Saints. It is an XI century mosaic icon of the Blachernae type, above the main altar of Kiev's Holy Wisdom Cathedral. The Mother of God is depicted against a golden background, standing with upraised hands on a quadrangular gold platform.

In some Icons of this type [but not in the mosaic Icon], Christ is depicted within a mandorla, an oval or circle, symbolizing the glory of Heaven, or the Divine Light.

The Icon is called the "Unbreakable Wall" because for ten centuries it has remained intact, in spite of the fact that both Kiev's Holy Wisdom Cathedral and the city have been damaged several times. An ancient description of this Icon has been preserved: "A gigantic full-length portrait of the Theotokos.... She stands upon a gold stone, as an unshakable foundation for all who resort to her protection. Her chiton is blue, and she wears a scarlet belt. Hanging from it is an embroidered cloth with which she wipes away so many tears.