The Fairies, or Sidhe, have often been observed dancing in dense and dark woods, frolicking around circles of mushrooms or fungus, circles of grass or grain laid flat by their cavorting and dancing, or moss covered stones laid in circular form. Some say Sidhe magic resides in these circles, even when they are not present. The yew tree is often found in proximity to fairy circles, and care must be exercised to never harm it. Intruding into these sacred places carries dire risk.
If you inadvertently find yourself in one of these places, watch what you say, and take care where you tread, lest the ire of the fair folk is stoked and brought to life. Offer your apologies, leave an offering, and hasten to depart. Many who have not heeded this advice have been enticed or ensnared by sorcery to dance with the Fair Folk in their fairy rings… and they are either never seen from again, or return many years later untouched by the passing of decades and with minds clouded or fogged by ancient magic.