Once brought to Loreto, Mary's plain house was nestled inside a sumptuous marble shell, the masterpiece of a Renaissance genius.
Pope Julius II had it designed by Donato Bramante in 1509, but it took no less than seventy years to complete it – employing the talent of Andrea Sansovino, Ranieri Nerucci, Antonio da Sangallo the Younger and many others artists.
Source: http://www.italianways.com