In the past, http://poehali.org/maps/ offered a free-of-charge download of Soviet military topographic maps of many areas in the world. Those maps are in the public domain. Now, this site redirects to http://mapstor.com , a website offering a low-cost archived download of those maps, but not free-of-charge. http://www.topomapper.com/ allows for interactive looking at Soviet military maps, but only for parts of the world and only up to a scale of 1:100.000, even for areas mapped at 1:50.000.
Where can I download free-of-charge public domain Soviet military maps?