The end of July until early August each year, local volunteer groups will hold the activities for watching fireflies (ホタルの鑑賞会) and they will provide flashlights and introduce the visitors into the park every night.
For the activities, they construct black clothe in the side of the road beside the park to avoid the car light impact to the park.
Although I do not understand Japanese and volunteers can not speak English or Chinese, they are still very friendly and also lead us into the park.
However, at night the way to Chaoyang Park do not have street lights. It is very dark and car need to be careful.