[ds5400]

I've been to all the stone circles on nefarius map and activated all the switches but nothing happens.

[Arkain]

Each stone circle features three switches which result in a minor earthquake and a stone guardian spawning within the circle. The guardians carry the relicts, save for the one near Lobart's farm. Upon further investigation you will find out that the guardian has already been disposed off by the paladins. The relic has been taken by them and can be gained from Lord Hagen.

In short: kill the guardians near Sekob's farm and the forest, visit the paladins.