The stamp of the month May 2021 is the Finnish Himos Jämsä stamp.
Himos Jämsä is a ski resort with 12 kilometers of ski and snowboard slopes.
It also offers 15 lifts, lighting in the evening, accommodation for rent, a sauna world and much more. For more information, here is the website of the Ski Resort Himos Jämsä.
Researching this stamp was like a little trip for me and made me want to visit this place myself. There is also a lot to do in summer.