The red-shanked douc langur on Son Tra peninsula in Da Nang city. (Photo: Le Hai Son)

The competition encourages amateur and professional photographers to join efforts to protect the environment by developing sustainable relations between humans and nature. The photographs can feature natural and biodiversity beauty, the interaction between humans and nature and daily activities related to the environment. 

There is no limit to the number of photos submitted by each photographer. The award ceremony is expected to be held in November, and the 100 best photos will be showcased at an exhibition in December.