The Blue Mountains cut off Sydney and the coastal plain from the interior. The first convicts to arrive at Botany Bay, their geography not inspired by their journey halfway around the world, believed that on the other side of these mountains lay ‘China and the Indies’. For nearly 20 years no one – escapee or explorer – managed to get beyond this strangely beautiful but impenetrable geological feature.

The Blue Mountains are really just the beginning of the 1,000-metre-high inland plateau, which has been fissured with steep valleys and cliffs by aeons of erosion. They received their name from the characteristic blue haze which hangs above them – a poetic feature with a prosaic explanation (oil evaporating from the eucalyptus trees).

The Blue Mountains National Park is one of the best, and most popular, in all the country (www.nationalparks.nsw.gov.au). Yet even when the tourist towns here become a traffic nightmare at summer weekends, you’re never far from the scenery of spellbinding isolation.

Head west from Sydney on the Great Western Highway. The Blue Mountains Information Centres are at Glenbrook, Katoomba, Lithgow and Oberon, and here you can pick up details of all the activities and sights in the park, as well as maps of the superb bush walks. Further on, the town of Springwood is something of an artists’ colony, with several interesting galleries.

If you plan to stay in the Blue Mountains, head on to Katoomba, which is the best base. The main sight here is the Three Sisters, stone tors which rise spectacularly above Jamison Valley. (These are said to be the daughters of an Aborigine chief, who turned them to stone to prevent their capture by a rival tribe.) Many worthwhile bush walks – both long and short – start from Katoomba, and even some of the shortest have superb views.

Also worth seeing are many gorges, some fine caves and also waterfalls.

If you don’t fancy driving out here, you can pick up a day rail/bus tour at Sydney Central Station and Circular Quay Station (www.transportnsw.info).