Looking up from just in front of the high altar, one sees the top of the baldacchino (canopy) that covers the altar and then in the ceiling, the mosaics that form most of the wall and ceiling decoration in St. Mark's Basilca. Unlike most Catholic cathedrals that use frescoes to adorn walls and ceilings, St. Mark's makes use of mosaics that include an enormous number of tiles covered in gold leaf. From this architectural feature, St. Mark's has come to be known as Chiesa d'Oro, Church of Gold.