The old Tartu Observatory is known internationally for its connection to Friedrich Georg Wilhelm von Struve and the Struve Geodetic Arc, of which it is the first reference point.
The Tartu Observatory was founded at the Imperial University of Dorpat as it was reopened in 1802. The observatory building was completed in 1810 on the Toome hill in Dorpat. The instruments were installed in 1814 by von Struve who subsequently started observations. In 1824, a 9" Fraunhofer refractor arrived, the largest achromatic telescope in the world at the time. When von Struve began assembling his Geodetic Arc in 1816, the doorstep of the observatory became its first point.
Source: http://en.wikipedia.org/wiki/Tartu_Observatory
