The Observatory of Ulugh Beg in Samarkand, Uzbekistan, 1420
(From "Samarkand" by Alexey V. Arapov, 2004, SAN'AT)
An imaginary restoration of the Observatory of Ulugh Beg in Samarkand.
When the site was overall excavated in 1951, the plan of
the original building was restored with bricks as its bases.
A long horizontal vaulted part behind the newly built Riwak (gate) is
the current roof of the underground part of the rear half of the quadrant.
A perspective drawing and cross-section.
(From "Samarkand" by Alexey V. Arapov, 2004, SAN'AT)
The diameter of the building is 46 meters and the height 30 meters.
There could have been many other large observation instruments here.