At the first location (co-ordinates above) you will find a building. Count the number of windows, all provided with a closable lid. The number of LARGE windows is 1. The number of SMALL windows is A.
The second location is N59°27.(50*A+139) E018°06.(50*A+356), where you will find a blue sign. At the bottom of the sign is a timescale (in red) with references in years above it. The first variable is above the words "Äldre järnålder" - pick on of the years there which is B and the second is found above the text "Medeltid", we'll call it C.
At the third location, situated at N59°27.(A+B+168) E018°06.(C/2-A-6), you will find the cache.
Ybbx haqre n obhyqre gur fvmr bs lbh.