This World is far older than you can imagine. We do not walk alone in it, neither beneath the Sun, nor under the light of the Moon.
The Fay
The Fays (or Fey, or Fairies) are closely associated with humans but, at the same time, completely other. Spriggans, Corrigans and the rest inhabit our world, are thoroughly "natural," and yet, at the same time, they are in some measure otherworldly, too.
Fays are connected to your family, and for some the connection is very strong indeed.
"Mythical" Creatures
There are those who dismiss the existence of mythical creatures out of hand. Indeed, for some people, such creatures are a positive embarrassment, because belief in them accords poorly with modern science.
But such people miss the truth that lies behind the old legends; they fail to understand both the poetic truth, and the full Truth of things, because they are mired in their own skepticism and arrogance.
It is always a mistake to assume that people of centuries ago were fools. They may not have had a scientific viewpoint; they may not have enjoyed a modern education. But none of that means they were ignorant, nor foolish.