Hirvepark (Deer’s Park) was created in the former moat in front of the bastions. In 1865 the dendrology park and arboretum were established by the Gardening Society of Estonia at the bottom of the filled moat. It was a place where the exotic plants were tested and the saplings of the decorative plants were multiplied. It was a favourable microclimate that brought forward the construction of the dendrology garden. Deer, whom the park owes its name to, used to live there at the 1930th. The park was hardly damaged during the war and still remains the stand rich in species. The famous public meetings, aspiring to gain Estonia’s freedom from the Soviet Union, changing the history of the nation, were held there during the so‑called Singing Revolution in the late 1980s .

Hirvepark is unique among the parks of Estonia in general and Tallinn in particular from the point of view of the structure of ligneous plants. Many of the trees in the park are remarkable for their age, dimensions and rarity.

The common maple „Cucullatum” with socket‑shaped leaves, which can be seen only in a few collections, can be considered the most rare tree in the park. The Hirvepark’s maple is also one of the largest in Europe. There were 102 species of ligneous plants growing in Hirvepark in autumn 2007.