Návštěvníci is a Czechoslovak sci-fi TV series filmed between 1981 and 1983 by Czech director Jindřich Polák. The 15 parts were co-produced with television-companies of the Federal Republic of Germany (West Germany at that time), Switzerland and France. As an additional 16th part for Germany a "Making of" was produced under the title "Besuch bei den Besuchern" (Visiting the... imdb.com