Beltaine(or Beltane) is the last of the spring fertility festivals. At this time, Pleiades rises just before the sun does, which would mark the beginning of Summer(On Samhain, the beginning of winter, Pleiades does not rise until sunset).
This is a very magical time, just as during Samhain. It is said that the Queen of Faeries, herself, rides out on her horse and attempted to bait people into Faeryland. Legend has is that if you sit beneath a tree on Beltaine, you may hear or see the Queen. Other traditional beliefs of Beltaine focus on a battle between the May Queen and the Queen of Winter.