Zelenogorsk (Russian: Зеленогорск, IPA: [zʲɪlʲɪnɐˈgorsk]) is a closed town in Krasnoyarsk Krai, Russia, located on the left bank of the Kan River 180 kilometers (110 mi) above its confluence with the Yenisei River.

It was formerly known as Krasnoyarsk-45 (Красноя́рск-45) and was involved in enriching uranium for the Soviet nuclear program.

[citation needed] As a closed town, it went under the code-name Krasnoyarsk-45 until Russian President Boris Yeltsin decreed, in 1992, that such cities could use their historical names.

As is the tradition with Soviet towns containing secret facilities, the designation "Krasnoyarsk-45" is actually a postcode; it implied that the place was located directly in the city of Krasnoyarsk, but really 160 kilometers (99 mi) from it.

Access is possible only by having a special entry permit issued by the city's authorities.