Northern Lights

After many years spent touring the sunshine countries,spain,france,portugal,etc we have decided to have a complete change in 2013 & go north to visit belgium,holland,denmark,sweden & then up to Tromso norway by september to see the Northern Lights,after visiting the North Cape in the arctic circle.I have had a lifetimes ambition to see the northern lights & being retired this is my chance.I would greatly appreciate any tips from members who have done these countries,ie must see places,great campsites,etc all comments will be welcome.