Aurora Borealis

where can you see them?

Aurora boreali generally occur in places of high northern latitudes (while aurora australis occur in high southern latitudes). They are most clearly seen at night against a dark sky.

Iceland A green slightly curved aurora borealis over hills.
Sweden Bright green and curvy northern lights over trees.
Norway Light green aurora borealis that also has hints of blue and purple over a lake surrounded by snowy mountains.