De underjordiska (Swedish)
De underjordiska (the underground ones) are a hidden, invisible people in Swedish folklore who live parallel to humans in an underground world beneath hills, meadows, and farmyards. They maintain their own farms, cattle, and paths called vitterstigar or onstreck that humans must never obstruct. These beings are most prominent in northern Swedish folklore, where they are often called vittror or vitterfolk, and are closely related to the Norwegian huldrefolk and the Gutnish "di sma undar jordi" (the little ones under the earth). They are generally invisible but can appear to those with second si