100 mill years ago there were a rich volcano activity in a 20 * 20 km area north of Höör. Today the craters of the volcanos are still visible in the landscape as soft round hills covered with trees.
This series of caches will show you a few of the volcanos.
At Rallate you will find a big group of basaltic columns from the crater, very close to the road.
It was dificult to find a stable position because of all the big trees around, so please use the hint if you need it.