This Museumkaart (Museum Card) from De Nederlandse Museumvereniging (the Dutch Museum Association) gave, if filled in and completed with a valid stamp, free access to approximately 170 museums in the Netherlands during the year 1981.
This was the first year the concept of a Museum Card was developed. Until today it’s still in use, covering approximately 400 museums with annual 900,000 Museum Cardholders (2013). (Source: Wikipedia)