Ulugh Beg Observatory
LocationUzbekistan
Year1420
Size40 m sextant
OperatorTimurid court
About Ulugh Beg Observatory
Built by the mathematician-king Ulugh Beg on a hill in Samarkand. Its enormous meridian arc, the largest instrument of its kind, measured star positions with unmatched precision for its day. His catalog listed over 1,000 stars. Torn down after 1449 and located again by excavation in 1908.