אינדקס
The Sumerians in ancient Mesopotamia achieved over one hundred "firsts" for human civilization. Advances in writing, agriculture, science, mathematics, medicine, and astronomy. See more in Season 6, Episode 3, "The Anunnaki Connection."
A new subterranean realm is discovered deep in the caves of Vietnam, in this clip from Season 18, "Secrets of Inner Earth."
HANG SON DOONG ON NATGEO - World's Biggest Cave
Son Doong Cave in the remote parts of Central Vietnam is a whole another universe in itself and holds some of the world’s most incredible natural wonders within. Visiting the Son Doong cave is a once in a lifetime experience and surely one of the top must-do journeys in the world!
