In 1840, the 3^rd Earl of Rosse ordered that the «Leviathan of Parsonstown», the most powerful telescope at that time, be set up here. Its lens (183 cm) was cast in a furnace, which was specially installed at the top of the feudal mound and fired with peat from the nearby marshes. Astronomers from Australia, Russia and the United States came to admire this instrument, which remained in use until 1908.