Hiisi Portti (Hiisi's Gate)
Not independently attested in folklore literature. No Finnish source describes a portal called 'Hiisi's Gate'; the resemblance is to Hiidenportti, which is the name of a national park in Kainuu, not a folklore phenomenon. Hiisi is a genuine figure of Finnish and Karelian tradition (appearing in the Kalevala), but the gate/portal mechanics here are invented.