Only once a year, in the first full moon of October, in the northern part of Thailand, an inexplicable phenomenon happens. At sunset, on the surface of the Mekong River fly pink, orange and green fireballs.
After a few seconds flight, the fireballs are completely dissolved in the air. For centuries, locals have not told anyone about this strange phenomenon.
They still are absolutely convinced that the fireballs are coming from the mouth of the great serpent Naga, which has seven heads and according to ancient legend lived in the Mekong from time immemorial.
According to the people of the village, whenever Naga decides to come out of the river, she spews a huge amount of fireballs.
The phenomenon of flying fireballs is known locally as bangfay phayanak. Each of the fireballs is the size of a chicken egg.
During the flight of the fireballs over the Mekong River, travelers from around the world gather, and scientists are trying to understand what this strange phenomenon is.
Locals say that many years ago, the fireballs appeared in March, April and May, but lately they can be seen only in the fall.
The flight of the fireballs over the Mekong River begins at six o'clock in the evening and continues until about nine o'clock. From the river, hundreds fireballs set off.
There is a legend that a fireball created a stairway to heaven, from which different gods descend to examine how we live.
During the festival of the Naga fireballs various shows are organized, offering local dishes and a race down the river with boats.
It is said that years ago, the U.S. military arrived there to investigate the phenomenon and having entered the water during the eruption of fireballs, had not returned.