A favorite holiday celebrated amongst most of the pagans and wiccans I know, it is unfortunately (or maybe fortunately) usually misinterpreted. The common intepretation of it these days makes it basically a holiday of sex, instead of fertility. This misplaces the joining of the God and the Goddess providing fertility of all things, and places it onto a solely human aspect, resulting in sex. Lots of it.

Note: From personal experience, if you throw a Beltane party... put down plastic tarps.