The cave was hounoured on the Vietnamese Google homepage together with 17 nations around the world, including the UK, Singapore, Thailand, Mexico, Sweden, Greece, Romania, Argentina, and Chile.
The cave, which has a large, fast-flowing underground river inside, had its entrance discovered by local resident Ho Khanh in 1990.
In 2009, the BCRA expedition team (British Cave Research Association) officially announced Son Doong as the world's largest natural cave. Shortly afterward, it completed the survey and measurement of the entire Son Doong Cave with a length of over 9km and a space of 38.5 million cu.m.
Therefore, to mark this special event, Google Doodle has chosen April 14 as Hang (cave) Son Doong's Day.
Professional geologists estimate that the cave was formed about 2 to 5 million years ago.
The cave is large enough for an entire 40-story skyscraper. Scientists have discovered remarkable geological formations in the cave, including the world's tallest stalactite.
The giant dolines in the cave allow sunlight to penetrate into them forming the lush tropical jungle and a unique ecosystem, which are home to many rare species, according to Google.
Son Doong Cave has drawn international attention and become a staple on adventure bucket lists for travellers from around the world.
World-renowned travel magazines and newspapers have repeatedly named Son Doong Cave as one of the best natural wonders and dream destinations for travellers.
