The Antikythera mechanism ( /ˌæntɨkɨˈθɪərə/ ant-i-ki-theer-ə or /ˌæntɨˈkɪθərə/ ant-i-kith-ə-rə) is an ancient analog computer designed to calculate astronomical positions. It was recovered in 1900–1901 from the Antikythera wreck, but its significance and complexity were not understood until a century later. Jacques-Yves Cousteau visited the wreck in 1978, but found no additional remains of the Antikythera mechanism. The construction has been dated to the early 1st century BC. Technological artifacts approaching its complexity and workmanship did not appear again until the 14th century A.D., when mechanical astronomical clocks began to be built in Western Europe. Professor Michael Edmunds of Cardiff University, who led a 2006 study of the mechanism, said:  This device is just extraordinary, the only thing of its kind. The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely carefully ... in terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa. —30 November 2006 The Antikythera mechanism is displayed at the National Archaeological Museum of Athens, accompanied by a reconstruction made and donated to the museum by Derek de Solla Price. Other reconstructions are on display at the American Computer Museum in Bozeman, Montana, the Children's Museum of Manhattan in New York, in Kassel, Germany, and at the Musée des Arts et Métiers in Paris. The mechanism was housed in a wooden box approximately 340 × 180 × 90 mm in size and comprised of 30 bronze gears (although more could have been lost). The largest gear was approximately 140 mm in diameter and had 224 teeth and is clearly visible in fragment A. The mechanism's remains were found as 82 separate fragments of which only seven contain any gears or significant inscriptions.