The UN's cultural organisation Unesco is meeting in New Zealand to discuss which sites to add to the list of most valuable natural or manmade treasures.
Sydney's Opera house is a candidate for the heritage list
Around 45 sites are in competition to be added to the World Heritage list.
The committee will also decide if any heritage sites are in danger from war, tourism, overdevelopment or neglect.
Those that could be deemed endangered include the Tower of London, the Galapagos Islands, Dresden in Germany and Machu Picchu in Peru.
The committee is also expected to reach an opinion on controversial Israeli excavations near the Al Aqsa mosque in Jerusalem.
SITES BIDDING FOR HERITAGE LISTING
Volcanic island of Jeju, South Korea
Sydney's Opera House
The committee will consider bids from 39 different countries in its week-long meeting in Christchurch.
"Each site is visited by a team of experts who assess the management plan presented by the authorities," Unesco spokeswomen Sue William said.
There are currently 830 sites on the World Heritage List, from Afghanistan to Zimbabwe, which has been added to regularly since 1972.
But deciding which sites to include on the endangered list could prove more important.
Last year Dresden was added to the list, threatened with losing its heritage status if the city went ahead with a controversial modern bridge.
The Galapagos Islands and the Inca city of Machu Picchu could also be under threat from the effects of mass tourism.
Plans for the construction of a 310m (1,016ft) skyscraper near the Tower of London could also threaten its status.
Unesco is also being lobbied by campaigners calling on it to protect six World Heritage sites from the impact of climate change.
Groups including Greenpeace and the Climate Justice Programme have been petitioning the body to list the locations, including Mount Everest and the Great Barrier Reef, as "in danger".