A cave containing some of the earliest known paintings, a vast network of roads built by the Incas, and a citadel in Iraq dating back to the fifth millennium BC; these are just three of the sites expected to get Unesco World Heritage status this week.

At least 30 natural and cultural sites are hoping to add their names to the list of 981 World Heritage sites around the world. Inclusion on the list has significant economic implications. World Heritage sites are eligible for financial assistance towards preservation. The status is also a powerful draw for tourists.

However, the World Heritage Committee will decide whether to strip London's famous Palace of Westminster of its World Heritage status because of planned skyscrapers which could impact on important views of the Houses of Parliament.

Two of Australia's most famous protected areas may lose their status too. The Great Barrier Reef, one of the most biodiverse places on Earth, is being threatened by climate change, destructive coral-eating crown-of-thorns starfish, and pollution. The committee may downgrade its status to "World Heritage in Danger".

Prime Minister Tony Abbott has asked Unesco to remove World Heritage status from part of the Tasmanian Wilderness, a huge rainforest, to allow logging in the site.

The Chauvet Cave in southern France

Curators look at cave paintings in the Chauvet cave in Vallon Pont dArc, France
Curators look at cave paintings in the Chauvet cave in Vallon Pont d'Arc, FranceAFP
The cave has more than 1,000 pictures, many featuring animals such as bison, mammoths and rhinos
The cave has more than 1,000 pictures, many featuring animals such as bison, mammoths and rhinosAFP

The cave, located in a limestone plateau of the meandering Ardeche River in southern France, contains some of the earliest known paintings, drawn more than 30,000 years ago.

The grotto has more than 1,000 pictures -- many of which feature animals such as bison, mammoths and rhinos.

The cave was closed off by a rock fall around 20,000 years ago and remained sealed until its rediscovery in 1994. More drawings are expected to be found in remote parts of the grotto.

The Citadel of Arbil, northern Iraq

citadel arbil
The citadel of the Kurdish city of Arbil in northern IraqAFP
citadel arbil
One of the entrances to the citadel of Arbil in Kurdistan, IraqAFP

The Citadel of Arbil is a tell or occupied mound in Kurdistan, northern Iraq. Some believe it is the oldest continuously inhabited town in the world; the earliest evidence for occupation dates to the 5th millennium BC, and possibly earlier.

The Qhapaq Nan, or Inca Trail, Argentina, Bolivia, Chile, Colombia, Ecuador and Peru

inca trail
Hikers follow one of the best-preserved sections of the Inca Trail in BoliviaReuters

The Qhapaq Nan is a huge network of roads once used by the mighty Inca Empire that snake through the high snowy peaks of the Andes.

The trails cover more than 30,000 kilometres (18,600 miles) and go through six countries; Argentina, Bolivia, Chile, Colombia, Ecuador and Peru.

The Chaine des Puys, central France

The Chaine des Puys,a volcanic chain of 80 volcanoes over a distance of 32 km, near Clermont-Ferrand, France
The Chaine des Puys, a chain of 80 volcanoes near Clermont-Ferrand, FranceAFP

The Chaine des Puys is a chain of 80 extinct volcanoes covering a distance of about 40 kilometres, near Clermont-Ferrand, France

The chain includes 48 cinder cones, eight lava domes, and 15 explosion craters. The last eruption was around 6,000 years ago.

The Rani-ki-Vav stepwell, Gujarat, India

People stand on the edge of The Ran Ki Vav Stepwel, said to have been constructed by  Udaimati, The Queen of Bhim Deva, 1022 to 1063
People stand on the edge of The Ran Ki Vav Stepwell, said to have been constructed by Udaimati, The Queen of Bhim Deva, (1022 to 1063)AFP
worker sweeps the carved walls of The Ran Ki Vav Queens Stepwell
A worker sweeps the carved walls of The Ran Ki Vav (Queen's) StepwellAFP

The Rani-ki-Vav stepwell, on the banks of the Saraswati River in Gujarat, is thought to have been built by Udaimati, The Queen of Bhim Deva, in memory of her late husband Bhimdev I (AD 1022 to 1063).

According to its official nomination document, the site was designed as an inverted temple highlighting the sanctity of water, and is divided into seven underground storeys of terraced walls with pavilions and buttresses.

The Great Barrier Reef, Australia

An aerial view of Vlassof Cay in the Great Barrier Reef
An aerial view of Vlassof Cay in the Great Barrier ReefGetty
great barrier reef dying
An aerial view of coral bleaching in the Great Barrier Reef, affected by global warming and increased acidity in the seaReuters

The Great Barrier Reef is considered in poor health and Unesco will vote on whether to downgrade its status to "World Heritage in Danger".

It is under growing pressure not just from climate change and the destructive coral-eating crown-of-thorns starfish, but agricultural run-off and rampant coastal development linked to mining.

The Tasmanian Wilderness, Tasmania, Australia

Mt Anne (capped in cloud) from High Shelf Camp, Southwest National Park, Tasmanian Wilderness World Heritage Area
Mt Anne (capped in cloud) from High Shelf Camp, Southwest National Park, Tasmanian Wilderness World Heritage AreaJJ Harrison

The Tasmanian Wilderness covers nearly 1.4 million hectares of Tasmania.

Prime Minister Tony Abbott, who favours more access for loggers, has requested Unesco remove its World Heritage status from 74,000 hectares (183,000 acres) of the area, claiming it was not pristine -- but this could be rejected at the meeting.

The Palace of Westminster, London

the Houses of Parliament on the banks of the River Thames
The Palace of Westminster, home to the House of Lords and House of CommonsGetty
nine elms development
An artist's impression showing some of the skyscrapers planned for Vauxhall and Nine Elms along the Thames

The Palace of Westminster may lose its World Heritage status over concerns there aren't enough restrictions governing the development of skyscrapers in London.

The committee warned that "there do not seem to be defined settings or overall agreed constraints in place to ensure that new tall buildings do not impact on important views and other attributes of the property".