Sub Arini is one of the oldest parks in Romania. The municipality of that time established the park on a 22 ha area and built it between 1856 and 1865. Wolfgang Seifried was the engineer who developed and oversaw the works execution.
Between 1857 and 1858, the two main alleys were built along the former ditch of the Swimming School and the Seviş stream. At the same time, various species of trees were planted, the most prominent being, of course, alders (arini).
The dike was built in 1859, and a year later the bridge over the Trinbach brook. In 1865, the Sub Arini Restaurant was opened (today's Bolta Rece).
Since 1881, the park has been under the care of the Society for the Beautification of the City, which planted more trees. The greenhouse was built in 1883, followed by the first artesian fountain in 1894. The music pavilion was built in 1898, and every Sunday the military band held performances there. Since 1904, the park was fitted with electric lighting.
The municipal stadium, first known as the Physical Education Stadium, was opened in 1927 on the southern edge of the park. Between 1977-1981, the stadium was fitted with concrete stands for 12,000 spectators. In 1982, the capacity of the stadium was upgraded to 24,000 seats.
In 1938, the bust of Mihai Eminescu, cast by the sculptor Radu Moga, was unveiled. In 1979, the municipality started to pave the main alleys, and replaced the old music pavilion with a new one. Also, the artesian fountain was refurbished. During the same time, the children playgrounds were built.
Today, the park is home to 68 plant species (of which about 30 are exotic) and 95 sedentary or migratory bird species. The visitors could admire native species, such as alders, linden trees, chestnuts, sycamores and other trees (some of them over 150 years old), North American species, such as blue spruce, white pine, walnut, rock maple, tsuga, red cedar or Douglas fir, and trees from the Far East: Japanese barberry, ginkgo biloba and the Caucasian fir.