An aurora, also known as a polar lights or northern lights, is a natural light display in the sky, predominantly seen in the Arctic and Antarctic regions.
The stamp shows a great music band - Children Of Bodom :-). They're from Finland and play metal music. Some time ago I was on their live show in Warsaw ;-). I also got autographs from Alexi, Roope and Henkka :-)
These days in Poland we have beautiful winter weather - snow has finally appeared! :-) , The view shown in the picture was surprising for me! I have always linked Lapland with snow ;-). It is great to discover another side of a region through postcards!
There is the Helsinki Cathedral on the postcard. The church was built from 1830-1852 in the neoclassical style. It is one of the most popular tourist attractions in the city :-).