The valley became famous for the Catopsilia butterflies, whose density was unmatched anywhere else in the world. In the spring, around the time of the Dragon Boat Festival, the air would be filled with myriad dancing butterflies in their mating season, and it would seem as if heavenly maidens were showering down petals from the sky.
美濃的「黃蝶翠谷」，黃蝶密度高居世界第一，每年端午前後的「發生期」高峰，萬蝶共舞，宛若天女散花。