In 1985 the Faroe Islands issued a set of 4 stamps, one with a map showing all(?) the lighthouses, and the other three showing individual lighthouses. The map of the Faroe Islands shows the locations of 22 lighthouses. According to the Danish lighthouse service the Danish Administration of Navigation and Hydrography operates 27 lighthouses on the Faroe Islands. The web page “Lighthouses of the Faroes” https://www.ibiblio.org/lighthouse/fro.htm  describes 18.