So, the general consensus I’ve found concerning lore with trees and portals concerns faefolk! This made a lot of sense to me actually, as I’ve always associated this concept with the fae. There are more natural structures (like faerie rings) that once a mortal steps into or passes through, they are thus thrusted into another realm unlike our own. I found in a post on the internet that “an entrance to the faerie lands can be found at the trunk of a tree.”(I’ve also read this in books that are on the fae). With that, many people often leave offerings to the fae at their favorite trees, usually an oak or hawthorn tree. Hawthorn trees are especially important to the Celts and the lore concerning fae folk. (I may make a post about this later because it’s interesting). I also found other folklore of odd structures made from trees, and people claiming they are portals to the devil and whatnot. Nonetheless, people are seemingly fascinated but fearful of these structures, and consider them portals into other realms and a nexus of supernatural occurrences. Trees in a span of mythology and humanity are hubs of knowledge and creation, so the origins of these myths and folklore are not unusual.