The University of Tartu Old Observatory (Estonian: Vana observatoorium) is a historic astronomical building situated on the campus of the University of Tartu in Tartu, Estonia. Constructed between 1808 and 1810, the observatory was designed in a Neoclassical style by architect J. B. Lentz. It became the first dedicated site for astronomical observation and instruction at the university, housing a series of scientific instruments, most notably a 7‑inch Fraunhofer refracting telescope installed in the early 1820s.
From its inauguration, the observatory served as the central hub for the university’s Department of Astronomy. In 1958 the astronomical institute was transferred to the newly built Tartu Observatory in Tõravere, and the old building was repurposed for other academic uses. Today it accommodates the University of Tartu’s Department of the History of Science and Technology and functions as a museum displaying historical scientific equipment and the heritage of the university’s astronomical research.
The Old Observatory is listed as a protected cultural heritage monument by the Estonian National Heritage Board, reflecting its architectural and scientific significance in the development of astronomy in the Baltic region.
