Markree Observatory

Markree Observatory was an astronomical observatory in County Sligo, Ireland. The asteroid 9 Metis was discovered from this observatory in 1848 by Cooper's assistant Andrew Graham using a comet seeker telescope. The observatory was also home to the largest refractor of the early 1830s, which had a 13.3-inch (340 mm) aperture Cauchoix of Paris lens; the largest in the world at that time. The observatory also housed a number of instruments and was operated to varying degrees throughout the 19th century.

The observatory is noted for its discovery of the asteroid 9 Metis in 1848 as well as a 60,000 item star catalogue of the 1850s. In the later 1800s it was operated again after a brief hiatus, and gained note for its meteorological observations and research on double stars.