When did the Stone Forest of Yunnan Province begin to apply for world natural heritage status?

The Stone Forest was inscribed into the “World Natural Heritage Preselective List” decades ago.

In 1991, it began to apply for world natural heritage status.

According to relevant rules, each site can only have one chance for applying. In 1992, due to the insufficient technical preparation of the IUCN which at that time had carried out inspection and evaluation in the Stone Forest, and due to the provided documents lacking systematic comparison with other Karst sites in the world, the Stone Forest itself withdraw the application in order to succeed in the future.