Ulugh Beg Observatory

The observatory was built by Timur's grandson, the ruler and scholar Ulugh Beg; astronomers such as Jamshid al-Kashi, Ali Qushji and Ulugh Beg himself worked here.

At its centre was a huge marble sextant sunk into the ground, with which the scholars measured star positions and the length of the year with remarkable accuracy; the Zij-i Sultani catalogue lists more than a thousand stars.

After Ulugh Beg was murdered in 1449 the observatory was destroyed and forgotten until the archaeologist Vasily Vyatkin found its remains in 1908. The underground part of the sextant and a museum are open to visitors.