An area of rainforest in South America, roughly the size of Wales, is set to be protected with help of people in Wales.
The Size of Wales charity told BBC Wales it had raised enough donations to take on a new project in Peru.
Together with the charity's work in Guyana, it means some two million hectares of rainforest in the Amazon basin will be secured.
It comes with the eyes of the world on the region for the Rio Olympics and Paralympics in Brazil.
Size of Wales' acting director Lowri Jenkins said the Amazon rainforest provided "a stunning backdrop" to this year's Olympics, which ended at the weekend, drawing attention to the twin threats of climate change and deforestation.
Launched in 2010 with the support of Prince Charles, Size of Wales is supported by the Welsh Government and donations from people and businesses.
The charity said it had already helped plant more than four million trees and protect an area of rainforest the size of the nation, but now aims to double this.
Olympic organisers have committed to planting a tree for every athlete taking part in the Games.
Every one of the 10,500 competitors in the opening ceremony parade received a seed, which will be planted to create an athletes' forest at Deodoro.
Working with a partner organisation in South America, the projects will support indigenous groups in their efforts to secure legal rights to their traditional lands and forests.
Ms Jenkins said: "We're chuffed to be able to say we're helping to protect an area of rainforest the size of Wales in South America.
"We're currently looking at new projects in Africa, which would mean Wales is protecting an area the size of itself on both continents. That's an incredible achievement for our nation."