Dolgoprudny, city, Moscow oblast (province), western Russia. It is situated north of Moscow, where the Savyolovo railway crosses the Moscow Canal, linking the capital with the Volga River. Dolgoprudny appeared in the first Soviet five-year plans as a centre for airship construction. It now has machine-building and engineering industries. It is the site of the Moscow Institute of Physics and Technology, the Central Aerological Observatory, and the Pryanishnikov All-Russia Research Institute of Fertilizers and Agropedology. Pop. (2006 est.) 78,415.