The Governess General Mary of Hungary, half-sister of Charles V, enlarged the main corps de logis (main block) to include a grand gallery overlooking the park. A gallery was an essential architectural requirement in 16th century aristocratic residences. It was open to the outside on the ground floor, and was used as a reception area on the first floor, where it was richly decorated with works of art. The Archdukes later went onto add a second floor to Mary of Hungary’s gallery.