Countless butterflies filled the bamboo forest.
Butterflies are all over the trees, on rocks, and on the ground.
This is the Honghe Butterfly Valley in Jinping County, Yunnan Province, southwestern China.
From May to June every year, the so-called 'butterfly explosion' unfolds, in which butterflies that have grown from caterpillars to adults take flight all at once.
Last year, the number was 150 million, the highest in ten years, and this year it is expected to exceed 100 million.
[Yang Jeon / Curator, Honghe Butterfly Valley Museum: This year's butterfly explosion is about 15-20 days later than usual.
The number of butterflies is expected to be similar to last year.]
In 2009, scholars discovered more than 320 species of butterflies in the Honghe Butterfly Valley.
The warm, humid weather and abundant bamboo, the main food, make it a perfect place for breeding.
[Chinese state-run CCTV report: With an altitude difference of 2,900 meters, the three-dimensional climate is clear, forest resources are abundant, and plants are diverse, so it is a good condition for various kinds of butterflies to breed.]
After opening to the public in 2010, the Honghe Butterfly Valley Over 1.8 million visitors attended.
To prevent habitat loss, authorities are creating conservation ordinances and educating visitors.
The butterfly explosion has been known to have been found in only two places around the world: Mexico and the Hunghe Butterfly Valley.