It’s easy to take modern air travel for granted. Before a lack of legroom and Wi-Fi ranked among our top complaints, globetrotters had to hunker down for trips lasting upwards of 40 days if they wished to leave the continent. While most locations on the opposite side of the globe can be reached in less than a day now, there are still plenty of places that require an epic trek.

This video from the YouTube channel RealLifeLore highlights some of the world’s most difficult destinations. The list includes remote islands without airports, like the Kerguelen Islands in the Indian Ocean and Pitcairn Island in the Pacific, as well as treacherous mountaintops. Mount Everest may be the highest summit on Earth, but it’s hardly the least accessible. Gangkhar Puensum in Bhutan is in the running for that title: Thrill-seekers are banned from climbing the mountain by the government. For more out-of-the-way destinations that are actually inhabited by people, check out our list of the most isolated towns on Earth.