The building was designed by Mauro Codussi and constructed between 1496 and 1499. It has five bays, of which the central bay is the widest. This bay incorporates a two-storey gateway, with the large clock face above, topped by a single storey tower with a depiction of a Lion of St Mark against the night sky, while two blackened bronze figures intended as giants but known as the 'Moors' stand on top and ring a bell on the hour. The clock mechanism, dating from 1499 and much restored since then, drives the main clock face, which consists of several concentric dials. The outermost displays the number 1 to 24 in Roman numerals, and a hand embellished with a depiction of the sun indicated the hour. The second dial depicts the twelve signs of the zodiac, picked out, like the inner dials, in gilt on an enamel blue background. The inner dials indicate the phases of the moon and sun. The mechanism also moves a display above the clockface, where a niche with a depiction of the Virgin Mary and baby Jesus lies between two displays: the hour in Roman numerals and the minutes (in multiples of five) in Hindu-Arabic numerals. On Ascension Day, statues of the three kings pass in front of the displays. Terraces were added to the tower by Giorgio Massari in 1755, but it has otherwise been little altered. Major renovations have obscured the structure behind scaffolding for several years. Now though, this extraordinarily elaborate timepiece is on public show again, in full working order, and delighting visitors and Venetians alike, as it has done for more than 500 years.'