It was minted in Ekaterinburg, a city in the Ural Mtns several hundred kilometres east of Moskva. They did also mint 5 kopeks in silver, but it was not as popular as the 5 kopeks in copper. One of the curious effects of the large 5 kopek coin is that the 5 kopek coin was large even in the USSR era, and still is in Ukraine - it is larger coin than even the 50 kopek coin.