Son Doong, the world's largest cave, has been closed to give it some time to restore itself without any human intervention, the news website of Vietnam Television reported on Thursday.
The cave, part of Phong Nha - Ke Bang National Park in the central province of Quang Binh, is expected to be reopened to the public next February, after the annual scheduled recovery period.
It was first opened to tourists on a trial basis in August 2013 and in the first eight months recorded 482 international visitors who paid US$3,000 each for a five-day tour, the website said.
Oxalis Adventure Tours, the sole tour operator, paid VND8 billion ($351,000) in environment fees, it said.
First discovered in 1991 by local resident Ho Khanh, Son Doong became famous worldwide in 2009 after it was explored by members of the British Cave Research Association, with Khanh’s help.
The explorers named the cave the world's largest. It is five miles long, 450 feet wide and 600 feet high.
With a network of at least 150 individual caves, a dense subterranean jungle and several underground rivers inside, Son Doong has been continuously named one of top destinations by many international travel magazines and websites.