[8] The Blue Mountains National Park is the most central of the eight protected areas within the World Heritage Site and it forms part of the Great Dividing Range.

In 1999, 37 walking tracks were added to the State Heritage Register, extending from Glenbrook and the Nepean River in the east; to Mount Tomah in the north; to Wolgan Valley and Newnes in the northwest; to Jenolan Caves and Oberon in the west; and in the south, numerous walks leading down the plateau from Katoomba, Leura and Wentworth Falls.

The latter two flow into Lake Burragorang, which is located just outside the park and is the site of Warragamba Dam, the major source of drinking water for Sydney.

The Blue Mountains and Great Dividing Range were formed about 50 million years ago, when the area was uplifted.

The park contains a small range of eucalypt species across a variety of habitats including wet and dry Sclerophyll, Mallee, swamps, wetlands and grasslands.

[12] This range of habitats supports a rich variety of fauna, including a third of Australia's bird species, and numerous mammals, reptiles and frogs.

[13] Notable endangered and endemic species include the Regent Honeyeater, Broad-headed snake and the Blue Mountains water skink.

A number of Blue Mountains sightseeing and adventure tour companies can assist visitors in safely experiencing these activities.

An exclusion zone of approximately three kilometres was created around Lake Burragorang to protect Sydney's water supply, but a through-track was allowed from Yerranderie to Balloon Pass, then further east, for the benefit of bushwalkers.