Beltane or Beltane is the Gaelic name for the festival that begins on April the 30th or Beltane’s eve and continues on 1st May
"this is one of the magic turning points of the Sacred Seasons, the veil between worlds is thought to be especially thin, and as a result many of the Fairy Host, the Sidhe and the Tuatha De Danann may be seen crossing between the worlds"
https://witchesofthecraft.com/2017/05/01/
Tuatha what?! Ever seen the movie Willow?