Sydneysiders have been doubly blessed by nature. Not only do they have a magnificent coastline right at their front door, but a 90-minute drive west puts them in the midst of one of the most spectacular wilderness areas in Australia—World Heritage Blue Mountains National Park. This rippling sea of hills is covered by tall eucalyptus trees and dissected by deep river valleys—the area is perfect terrain for hiking and adventure activities.

Standing 3,500-plus feet high, these "mountains" were once the bed of an ancient sea. Gradually the sedimentary rock was uplifted until it formed a high plateau, which was etched by aeons of wind and water into the wonderland of cliffs, caves, and canyons that exists today. Now the richly forested hills, crisp mountain air, cool-climate gardens, vast sandstone chasms, and little towns of timber and stone are supreme examples of Australia's diversity. The mountains' distinctive blue coloring is caused by the evaporation of oil from the dense eucalyptus forests. This disperses light in the blue colors of the spectrum, a phenomenon known as Rayleigh Scattering.

The Blue Mountains Visitor Information Centre is at the foot of the mountains on the Great Western Highway at Glenbrook, the first town you'll encounter when driving from Sydney. There is another information office at Echo Point in Katoomba.