More people are climbing Mount Everest than ever before and many of them are making a mess of it.
Tenzi Sherpa, an Everest trekking guide, posted a video of a garbage-strewn camp on the mountain recently, saying it's the dirtiest camp he's ever seen.
Frequent hikers and campers generally know that you should pack out what you pack in.
But one American climber who has been going to Mount Everest for years says some climbers are just leaving behind what they can no longer use.
"Mostly broken tents... some food scraps, packages... and some empty oxygen bottles."
The garbage is not just unsightly. Some of the waste is polluting the local watershed, which is putting the health of people who live down-mountain at risk.