A report has revealed that the number of World Heritage Sites affected by climate change has almost doubled in three years.
The International Union for Conservation of Nature (IUCN) says that the number of threatened places has grown from 35 to 62.
The sorts of issues that are affecting these sites include coral bleaching and glacier loss. In fact, coral reefs and glaciers are among the most threatened ecosystems on the planet.
World Heritage Sites are special places all around the world which have been chosen as being particularly important to the world's heritage, history and culture.
Because of this, they are given special protection to make sure that they are looked after and that future generations can benefit from them.
But this IUCN report suggests that climate change is damaging an increasing number of these places.
Currently, the UK (and its overseas territories) has 31 Unesco-listed sites.
Not too long ago, the Lake District in the north-west of England was given the title of a Unesco World Heritage Site.
But what exactly does it take to become a World Heritage site?
As a World Heritage Site, a place will become more famous so lots of people will visit it and learn about it.
It can get more money to help look after it so that people can enjoy the site for many years to come.
There are over 1,000 World Heritage Sites around the world, with more still being added to list.
There's a list of rules that a place should follow for it to become a World Heritage Site.
One of these is that a place must have an interesting story that shows how important it was in history.
For example, the Grand Canyon in Arizona, US tells us a lot about the history of the Earth and how it has developed over millions of years.
Another reason a place could become a World Heritage Site is if it is exceptionally beautiful, such as the Taj Mahal in India, which is famous for its amazing architecture.
A more unusual and less famous site is the Fagus shoe factory in Germany. It may not be as pretty as the Grand Canyon or the Taj Mahal, but it is important in the history of art and architecture so is a World Heritage Site as a result.
Yes, some places have been warned that if they don't look after their site properly, they could lose the World Heritage Site status.
One of these place is Liverpool. It's beautiful and historic waterfront was given Heritage status in 2004.
But some experts have warned that plans for new modern buildings to be used as homes and offices there could change the way it looks so much that Unesco change their mind.
Liverpool says it wants to work with Unesco to find a compromise.
And not all old sites can say they are World Heritage Site.
For example, St Paul's Cathedral in London has no status, but the Tower of London does.