In a momentous win for conservation, Colombia’s Serranía de Chiribiquete was officially expanded to 10.6 million acres today, making it the world’s largest protected tropical rain forest national park. It was also declared as a UNESCO World Heritage site in recognition of its “outstanding universal value” for nature and people.

Colombian President Juan Manuel Santos first announced the expansion of the park by 3.7 million acres in February, marking the culmination of decades of joint conservation efforts by environmental organizations, including WWF, and the Colombian government.

“This is a defining moment for the protection of key ecosystems in Colombia,” said Mary Lou Higgins, Director of WWF-Colombia. “This is also a very important milestone for the Amazon and for forest conservation globally. The expansion and recognition of this unique place as a World Heritage site is a significant step toward safeguarding it for future generations.”