What are the Blue Mountains?

The Blue Mountains are the specific part of the Great Dividing Range which separate the main settlement of Sydney, Australia, from the central highlands and interior of New South Wales.

They are about an hour's drive west of Sydney Australia. They gained their name Blue Mountains as a result of the blue haze that covers them when seen from a distance (especially in hot weather). That is the result of gases being released from the eucalyptus trees that cover them, but this blue haze is far less evident nowadays, due to the extensive building developments that have seen deforestation of the mountains.