Today there is only one known example of a complete Viking helmet in existence. This Viking helmet was excavated on a farm called Gjermundbu in Ringerike in central Norway. Gjermundbu is located in Haugsbygda, a village in northeast of Hønefoss, in Buskerud, Norway. The helmet dates to the 10th century. This helmet was made of iron and was in the shape of a rounded or peaked cap made from four plates after the spangenhelm pattern. This helmet has a rounded cap and has a "spectacle" guard around the eyes and nose which formed a sort of mask, in addition to a possible mail aventail. The eye guard in particular suggests a close affinity with the earlier Vendel period helmets. From runestones and other illustrations, it is known that the Vikings also wore simpler helmets, often peaked caps with a simple noseguard.