China has closed the base camp on its side of Mount Everest to visitors who don't have climbing permits.
Authorities have resorted to the unusual move to deal with the mounting waste problem at the site.
The ban means tourists can only go as far as a monastery slightly below the 5,200m (17,060ft) base camp level.
More people visit the mountain from the southern side in Nepal, but over the past years numbers have been rising steadily on the Chinese side as well.
The Chinese base camp, located in Tibet, is popular as it is accessible by car - whereas the Nepalese camp can only be reached by a hike of almost two weeks.
The world's highest peak has been struggling with escalating levels of rubbish for years, as the number of visitors rises.
The Chinese Mountaineering Association says 40,000 visited its base camp in 2015, the most recent year with figures. A record 45,000 visited Nepal's base camp in 2016-7 according to Nepal's Ministry of Forests and Soil Conservation.
Ordinary tourists will only be banned from areas above Rongbuk monastery, which is around 5,000m above sea level, according to China's state news agency Xinhua.
Mountaineers who have a permit to climb the 8,848m peak will still be allowed to use the higher camp.
In January, authorities announced that they would limit the number of climbing permits each year to 300.
On Chinese social media, claims have spread in recent days that its base camp will be permanently closed to tourists - but Xinhua cited officials denying that.
The official announcement about the closure was made in December, on the website of the Tibetan authorities.
It stated that three clean-up operations last spring had collected eight tonnes of waste, including human faeces and mountaineering equipment climbers had left behind.
This year's clean-up efforts will also try to remove the bodies of mountaineers who have died in the so-called death zone above 8,000m, where the air is too thin to sustain life for long.
Due to the cold and high altitude, these bodies often remain on the mountain for years or even decades.
