Lampyridae releases light energy and therefore is called firefly, and it is a famous "free of charge natural souvenirs" of the Okayama Prefecture. You will see tens of thousands of fireflies flying around the area of the Tenno Yahaha Shrine within 2 weeks of July 10 each year, and thus resulting in an excellent scene. Please take note that there are specified areas for enjoying firefly and you are not allowed to smoke or use torches within the area. During weekends, because of large crowds, photo taking will be forbidden as well.
Address: Kounoie, Chita-cho, Niimi city, Okayama prefecture