The Toome Hill, rising above Old Town, has always been strategic military position. Tartu's original settlement, Tarbatu, was established here in 600AD, and if you trace the hill's outline on a map, you can still see the shape of fortifications built here in the 17th and 18th centuries.
The western part of the hill is clearly dominated by the ruins of the 13th-century cathedral (Toomkirik) that has been decaying since the Livonian War (1558-1583). The sanctuary, which is still in a quite good condition today, accommodates the University’s history museum. Here you can get a broad overview of academic research and teaching in Tartu.
The old observatory of Tartu was constructed in 1811. It was the most modern one in Europe in the 19th century.References:
Easter Aquhorthies stone circle, located near Inverurie, is one of the best-preserved examples of a recumbent stone circle, and one of the few that still have their full complement of stones. It consists of a ring of nine stones, eight of which are grey granite and one red jasper. Two more grey granite stones flank a recumbent of red granite flecked with crystals and lines of quartz. The circle is particularly notable for its builders' use of polychromy in the stones, with the reddish ones situated on the SSW side and the grey ones opposite.
The placename Aquhorthies derives from a Scottish Gaelic word meaning 'field of prayer', and may indicate a 'long continuity of sanctity' between the Stone or Bronze Age circle builders and their much later Gaelic successors millennia later. The circle's surroundings were landscaped in the late 19th century, and it sits within a small fenced and walled enclosure. A stone dyke, known as a roundel, was built around the circle some time between 1847 and 1866–7.