A.GrīnbergsB.BaikaI. LukssJ.GraudonisJ.T.UrtānsK.G.ZīverssK.GrenviksP.HelmingsProject "Cult Identity"Riņņukalns Sacrificial StoneRiņņukalns SettlementV. AvotiņšW.F.Hacker
State archaeological heritage (State Inspection for Heritage Protection, No 2511). An ancient cult site and one of the first discovered settlements of the Stone Age that has been scientifically studied since the 19th century. In the settlement site plenty of remains of food of the ancient people have been found — fishbones, shells, also various artefacts. The Sacrificial Stone has two bowl-type hollows (35 x 30 x 2 cm and 32 x 30 x 2 cm}. The distance between the bowls is — 6.5 cm, distance between the bowl centres — 45 cm. Some scholars believe that the stone was used more for household needs – polishing, sharpening (V. Avotiņš, I. Lukss. From Burtnieki to the Sea (No Burtniekiem līdz jūrai). 1999). In the excavations many bone tools, harpoons, fishing hooks, awls, daggers, etc. were found. The stone is situated in the canes of the Salaca River bank, 4 m north of the bush that is between the river and Riņņi Hill, 15 m north of the Riņņukalns Settlement, in summer — 1 m south of the water, in a swampy place, in the canes. During high water period, it is completely under the water or mud. A very rarely found type of hollow stones (Only 3 such objects in Latvia). The Riņņukalns Hollow Stone is the earliest known. Research proves that Riņņukalns has been inhabited already since the 2nd millennium BC. (J. Graudonis, J. Urtāns. Traces of Antiquity (Senatnes pēdās). 1961). Nearby: Vecate, Vecate Park, Salaca’s rise, Tūtere Oak Site.
Beyond any doubt, the hollows had been artificially made by humans. It is possible that on its surface it was attempted to carve a third hollow; in any case, there is a spot where the surface looks polished. It was described by K. G. Zīverss (1875), P. Helmings (1875), K. Grenviks (1876) and others. The first reports by scholars about the Riņņukalns are dating back to 1896, at the 10th Congress of Archaeologists in Riga (W. F. Hacker) (Archive of the Scientific Council on Museum and Cultural Heritage, inventory No 15050 I). In former times there used to be a gently sloping delve that had become a hill filling up with cultural layer, consisting mainly of shell remains (Archive of the Scientific Council on Museum and Cultural Heritage, inventory No 29490 7314 -6). It is also called the bowl stone and is rather a rarity (A. Grīnbergs. The Unique Riņņukalns Hollow Stone has not disappeared! (Unikālais Riņņukalna dobumakmens nav pazudis!) – Vides vēstis, 07.2008.)