The Greater Blue Mountains is a UNESCO World Heritage site located in New South Wales, Australia. It covers over 1 million hectares and includes a vast area of temperate eucalypt forest, sandstone plateaus, waterfalls, and diverse wildlife.

The area is named after the blue haze that is created by the vast eucalypt forests, which contain more than 90 species of eucalypts. The eucalypts found in the Greater Blue Mountains are some of the tallest in the world, with some reaching up to 100 meters.

The Greater Blue Mountains is also home to many unique plant and animal species, including the Wollemi Pine, which is considered a "living fossil" and was only recently discovered in 1994. The area is also home to many rare and threatened species, such as the spotted-tailed quoll and the giant dragonfly.

In addition to its natural beauty and biodiversity, the Greater Blue Mountains is also significant for its cultural and historical value. The area has been home to the Indigenous people for thousands of years, and there are many important cultural sites and artworks throughout the region.

Visitors to the Greater Blue Mountains can enjoy a variety of activities, such as hiking, rock climbing, camping, and wildlife watching. There are also many scenic drives and lookouts throughout the area, including the famous Three Sisters rock formation in Katoomba.