atlasobscura: Vietnam’s Massive Cave Now Open For Tours! No one had seen anything like Son Doong cave until 1991, when a man named Ho Khanh happened upon its entrance in the Vietnam jungle. Due to the sound of a roaring river and the sheer drop into

atlasobscura: Vietnam’s Massive Cave Now Open For Tours! No one had seen anything like Son Doong cave until 1991, when a man named Ho Khanh happened upon its entrance in the Vietnam jungle. Due to the sound of a roaring river and the sheer drop into

atlasobscura: Vietnam’s Massive Cave Now Open For Tours! No one had seen anything