The production and sale of butter and cheese has existed in Åland since the Middle Ages. The first Åland dairy was founded approx. 120 years ago. Today, the dairy cooperative Ålands Centralandelslag (ÅCA) handles the Åland dairy production. ÅCA cheeses have won several awards, the most recent success being the 2012 competition for best Finnish cheese. The cheeses ‘Kastelholm’, ‘Ålands special’ and ‘Prostens magra’ came in second, whereas the Åland ‘Edam’ won third place. A total of 107 types of cheese were entered in the competition in 12 different categories. The Kastelholm cheese featured on the stamp got its name from the only medieval castle in Åland, located in Sund. The name is thought to originate from a traditional type of double cream cheese which was produced in Sund in the 1500s. Since then, cheeses with the name Kastelholm have been produced to some extent. In the 1920s, for example, the Kastelholm double cream cheese won several awards in a number of quality competitions. ÅCA’s current variety of Kastelholm cheese has tiny eyes and a 31% fat content. Kastelholm cheese must age for at least 6 months for the flavour to develop properly. With a savoury aroma, the aged cheese has a rather sharp and full-bodied taste that grows more intense as the cheese ages. Apart from being sold in Åland and Finland, Kastelholm can also be found in some parts of the Swedish market. The stamp photo was shot at Kastelholm castle.