The Great Dividing Range reaches one of its dizziest heights in the rainforest highlands of Barrington Tops National Park.

This World Heritage-listed park encompasses two linked plateaus that peak at a heady 1,577 metres at Polblue Mountain. Up here, the air is crisp and clean and crystalline rivers cascade down steep, forested gullies.

The park is home to more than 40 threatened species, including koalas, tiger quolls, powerful owls and rufous scrub birds but you are more likely to meet old acquaintances such as kookaburras, possums, wallabies and kangaroos.

Temperatures vary considerably between the foothills around Chichester Dam (170 m) and the Barrington Plateau (1,577 m). Night temperatures regularly drop below zero between June and November in the high country and heavy snow closes several roads. Some 4WD trails may also be closed at any time of year after heavy rain.

Generally, campers should plan to visit between late spring and early autumn. Light snowfalls on the snowplains are possible even in summer but you are much more likely to encounter cool, misty mornings and mild, clear days once the sun has burnt off any lingering low cloud.

Rainfall is relatively high all year but compensation comes in the form of lush rainforest and sub-alpine wetlands. These forests are at the southern limit of eastern Australia's great rainforests and provide a mix of sub-tropical, warm temperate, dry and cool temperate rainforest.

Campers and bushwalkers should be prepared for sudden weather changes. Cold and wet-weather clothing are essential all year round.

The park is well-supplied with camping areas, both within the park limits and in two State Forests on the park boundaries - Chichester and Barrington Tops. The southern camping areas are especially good for families, with rivers and creeks for kids to explore and swim in under supervision.

There is no charge for camping, except at Gloucester River - $5 per adult per night, $3 children). Firewood is not supplied in the park - bring a stove. Fire bans may be in place.

Camping on the edge of the park's southern reaches is provided at the Allyn River Forest Park and Telegherry River areas of Chichester State Forest. Access to Allyn River Forest Park is via East Gresford on Allyn River Road or via Dungog on Salisbury Road. Access to Telegherry River is via Dungog on Chichester Dam Road, then Wangat Road.

Dogs are permitted on leads and there is river and creek swimming near most sites.

There are three camping areas with drive-in access in Allyn River Forest Park: White Rock, Pademelon Park and Dobbie Rim. There is also an unpowered former forest worker's hut, Gunyah Hut, which sleeps six. Note, there are no toilets at Pademelon Park.

Telegherry River has five camping areas, including caravan sites at the popular Telegherry Forest Park, Frying Pan Creek and Coachwood. Note that these sites can only be accessed by conventional two-wheel-drive vehicles in dry weather. Another former forest workers' hut, Gumleaf hut, sleeps six people.

Park information is provided at the Williams River Day Use Area at the end of Williams Road.

The only camping area in the park near the Gloucester Tops area is at Gloucester River, 38 km south-west of Gloucester in Gloucester Tops Road. This is a well-equipped camp site with caravan sites, park information, toilets, picnic tables, fireplaces, barbecues, drinking water and river swimming.

For remote and spectacular camping (and unpredictable weather) head for the sub-alpine Barrington Tops plateau. Access is via Barrington Tops Forest Road from Gloucester or Scone, which includes 75 km of unsealed road. Many sites can be accessed in conventional two-wheel-drive vehicles. Others require 4WD or are walk-in only.

Camping areas on or near Barrington Tops Forest Road accessible to conventional vehicles include Polblue, Horse Swamp and Devils Hole (national park sites) and Manning River, Dilgry and Banksia (State Forest).

More remote sites can be accessed by 4WD in dry weather or by walk-in via Barrington Trail, off Barrington Tops Forest Road.

NSW National Parks can be closed at times of bushfire and bushfire danger. It is advisable to check with NSW National Parks and Wildlife Service before you set off. Either phone 1300 361 967 (within NSW) or (02) 9253 4600 or visit www.nationalparks.nsw.gov.au.