The cave was honored on the Vietnamese Google homepage together with 17 nations around the world, including the UK, Singapore, Sweden, Greece, 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 British Cave Research Association’s expedition team officially announced Son Doong as the world's largest natural cave. To mark this special event, Google Doodle has chosen April 14 as Hang Son Doong's Day. Following the icons of doodle bread, doodle phở, doodle of Hoi An city of Vietnam on the Google homepage, Doodle Son Doong continues to be a practical activity of Google to promote Vietnamese culture, cuisine and tourism to the world./.