This card came from Britt from Den Haag. 🙂
The Dutch gulden was the currency of the Netherlands from the 17th century until 2002, when it was replaced by the euro. The Dutch name gulden was a Middle Dutch adjective meaning “golden”, and the name indicates the coins were originally made of gold.
The exact exchange rate, still relevant for old contracts and for exchange of the legacy currency for euros at the central bank, is 2.20371 Dutch guilders (NLG) for 1 euro (EUR). Inverted, this gives EUR 0.453780 for NLG 1. So I guess my 25-gulden postcard equals about 11 euro. 😀