St. Mark's Cathedral, standing on St. Mark's Square in downtown Venice, is one of the most famous cathedrals in the Christian world. Its interior, from floor, wall to ceiling, is a meticulous mosaic. The architecture here combines the eastern and Western architectural features. It was originally a Byzantine building. Gothic decorations, such as pointed archways, were added in the 15th century. Renaissance decorations, such as railings, were added. St. Mark's Cathedral, also known as the "Golden Cathedral", is worth visiting.