Where was Gymkata filmed?

1985 film by Robert Clouse

Wikidata records no filming location for Gymkata (1985) at all, not a place, not even a country. There is nothing to pin, and this page says so rather than guessing.

Open the map → Wikipedia Source data

Why there is no pin

Its Wikipedia article also says it was filmed in Yugoslavia, without naming a place, so it is not on the map.