The Leviathan Telescope is a historic astronomical instrument located in Ireland. Built in 1845 by the astronomer William Parsons, the telescope was the largest of its time, with a primary mirror measuring 1.83 meters (72 inches) in diameter. It was primarily used for studying celestial objects and contributed significantly to the field of astronomy. The telescope is famous for its observations of the Andromeda Galaxy and other deep-sky objects. Although it is no longer in regular use, the Leviathan remains an important symbol of scientific achievement and innovation in the 19th century, showcasing the advancements in telescope technology during that era.