The cult of the seidas (sacred stones) existed on the whole vast area inhabited by Saami (Lapps) tribes. In Karelia the seidas sanctuaries are known on the Nemetsky Kusov and Russian Kusov islands near the Kem shore of the White Sea, near Paanajärvi Lake (on the Kivakka and Nuorunen mountains), on the Vuottovaara mountain, and possibly on the Big Vaara mountain on the northeast shore of the Petrozavodsk bay of the Onego Lake (1.5 kilometers to the East from Solomennoye).

Seidas are usually situated on the gentle rocky slopes.

Some of them are natural rocks and stones of fancy forms, other are laid up from natural stones, sometimes of enormous size.

Saamis believed that in this stones there live spirits that might help if one sacrifice them animals (usually reindeers) and things. The sacrifice usually was done near the seida, as the place were the stones laid was sacred. To those seidas that were situated at inaccessible places, the sacrifice was given by throwing to the seida the stones wetted in the sacrifice reindeer blood.

On of the first researchers of the seidas was Finnish scientist Matthias Alexander Castrén. He considered that seidas were some kind of idol, used by Lapps for witchcraft.

Modern researchers mark out two lines of belief in Saami ancient cults. One is the cult of seidas as hunting patrons (animal-looking stones) and the other (human-like stones) is the cult of forefathers.

The worship of sacred stones between Saami continued at least till the 1910-th years.