Declared the Eighth Wonder of the World and a UNESCO Biosphere Reserve, the Paine Massif is known as one of the most beautiful mountains on the planet. Formed around 12 million years ago, this geologic work of art is a magnet for trekking and climbing aficionados, making it the third most-visited park in Chile. The trekking circuits––known as the O and the W––are on the short list of must-visit treks from around the world. These hikes offer visitors turquoise lakes, pristine glaciers, gorgeous forests, and striking pampas, and are home to species including the Puma, Huemul (South Andean Deer), Ñandú, and Guanaco.