Ben de Jong Discusses the Russians and Their Secret Maps of the Netherlands
Ben de Jong, intelligence expert and fellow researcher and lecturer at Leiden University's ISGA, was cited in an article by Dutch newspaper 'het Algemeen Dagblad' regarding the topographic maps the Russians used during the Cold War.
The Sovjet Union possessed an incredible amount of very detailed maps of almost every part the world including the Netherlands. In some ways, the Russians knew more than we did, because Dutch maps only showed a limited amount of military locations.
Aivars Beldvas, a trader in maps from Riga and a former enlisted soldier in the Russian army, is in possession of a number of military ordnance survey maps of the Netherlands. These maps were not created in the Netherlands but were made by Russian hands. They were meant for military purposes.
According to Ben de Jong, the Russians used several different methods to obtain intelligence during the Cold War. First and foremost they used their secret services, the KGB and the GROe. Both of which, for instance, employed personnel that was stationed at the embassies in The Hague or other diplomatic branches. As well as placing intelligence personnel in the offices of Russian companies operating in the West. De Jong: 'Such a company would usually have a Dutch director, but the staff would be Russian. It doesn't take a lot of imagination to conclude that intelligence personnel were present as part of that staff.
It is also highly likely that planes and satellites were used to make recordings from the air to create these maps. The Russians have been in possession of satellites since the ‘60s. These, however, did not provide enough information on the details of, for instance, buildings and bridges. According to De Jong, was it not unusual for GROe personnel to travel incognito accompanying trucks from the East bloc, and as such were able to gather intelligence.
You can read more here (in Dutch) on how the Russians put the world on their maps.