The most enduring holiday memories are rarely found in tourist-trap hotels or crowded city-centre restaurants. They’re found in spectacular landscapes and heart-stopping wildlife encounters, often in remote locations. 

Sadly, some of these once-in-a-lifetime travel experiences are under threat, whether from climate change, deforestation, overtourism, or other factors. If you want to confront them in all their majesty, the window in which to do so is closing.

It’s an unavoidable reality that in visiting one of the destinations listed below, you risk becoming a part of the problem. After all, air travel accounts for a small but significant proportion – 2.5 per cent – of total global CO2 emissions.  

Happily, there are ways of seeing them – through sustainability-conscious tour operators, and while contributing to on-the-ground conservation efforts – that mitigate this risk.  

Here are seven world wonders with an uncertain future, plus tips on how to visit them responsibly.