A concept by "gates of balance101"...

I think that all the "triangles" (such as the Bermuda Triangle) are gates to other realms, worlds, etc. What do we know about gates? Well most are locked, which means they need a key, Who holds the key? Usually the owner of the house that the gate is protecting has the key to unlock it. Realms do not have owners so there must be a gate keeper who can hold the key and prevent others from entering. The gate keeper would probably not be aggressive because they keep the balance between the worlds.In order to keep the balance though, they would probably have to have powers in order to be able to fend off unwanted guests without harming them.

It's speculated that there are a total of 12 gates spread out evenly across Earth. With 12 gates comes 12 gate keepers and 12 keys. The gate keepers would probably not be immortal because the humans would get suspicious of them. I think that the gate keepers would be able to reincarnate themselves so they still have their previous memories. There's also the possibility that the gate keepers begin training an apprentice when they feel that their time on Earth is diminishing. The keys would not be just normal keys. If the gate keepers reincarnate, so do their keys. I would think that each time a "key reincarnation" happened, the keys would come back in different forms each time, Ex: human, plant, inanimate object, animal.

The whole idea is to keep balance between the 12 different realms.