Kaluga is a city in the European part of Russia, in the Central Federal District, the administrative center of the Kaluga Region. It is located on the banks of the Oka River. The population is 331,842 people (2021). The first mention of Kaluga was found in the letter of the Grand Duke of Lithuania Olgerd from 1371, which is considered the date of its foundation. Since 1389, Kaluga became part of the Grand Duchy of Moscow. In the period from 1505 to 1518, the city was an independent appanage principality, and later passed into the possession of Moscow. After the reunification of Ukraine and Russia in 1654, the Kaluga border fortress lost its former significance. Over the next century and a half, Kaluga experienced many dramatic pages of its history, such as the famine of 1723 and 1737, five fires that burned it to the ground, and in 1771 a plague epidemic broke out in the city.
The revival of the city began after Catherine II visited it in 1775. It was then that the Kaluga province was established, the coat of arms was approved. Spiritual and educational institutions were opened, a drama theater began its work. Most of the architectural monuments of Kaluga were built during that period. Kaluga reached its heyday in the XVIII–XIX centuries, thanks to its convenient location at the intersection of water and horse-drawn trade routes, it turned into a large commercial and industrial center. The main industries were rope and sail-cloth production. In the war of 1812, Kaluga became the largest rear base for Russian troops. After the end of the Civil War, the Soviet government "took a course" for the development of industrial cities, thanks to which a new stage began in the development of Kaluga. Factories and factories were revived. Mechanical engineering was actively developing. Kaluga is becoming an important industrial center. In 1944, the Kaluga Region was formed, the administrative center of which Kaluga is still today.
Today Kaluga is a major transport hub. The basis of the city's economy is the automotive industry, mechanical engineering and metalworking, food and light industry, electric power industry, construction materials industry. Kaluga is also a city of cosmonautics, museums and higher educational institutions.
The postage stamp depicts the State Museum of the History of Cosmonautics named after K. E. Tsiolkovsky, the monument to K. E. Tsiolkovsky, the stone bridge, the Kaluga Instrument-making Plant "Typhoon" and a panorama of the city.