The grandson of Tamerlane, Ulugh Beg, was more interested in observing the stars than in military conquest. In Samarkand, at the end of the 1420s, he built what was the largest observatory of the time, including a sextant that allowed him to determine the position of more than a thousand stars. The 11m portion of sextant that survived the ravages of time was rediscovered by Russian archaeologist Vyatkin in 1908 and remains as strikingly huge as ever.