Is it the World's Biggest Cave? More than three times the height of Niagara Falls, much of Vietnam's Mountain River Cave has remained untouched by humans until now. With exclusive footage, NGC reveals, for the first time in history, astounding evidence that this could be the largest cave in the world. Together with renowned expedition leader Howard Limbert, cave geologist Darryl Granger uncovers the formula for how the cave grew so grand.
The DVD-R is a non-rewriteable digital format that is compatible with most commercial DVD players. The DVD-R format is created with MPEG2 Variable Bit Rate Compression with stereo sound.
How our DVDs and DVD-Rs Differ
Customers who purchase programs in the NG DVD Exclusives Library will receive a non-interactive, play only disc. There is no chaptering information on these DVDs, but there are chapter marks approximately every five minutes, which make it easy to fast forward through a program. The DVD-R format provides the digital video and audio quality you expect from all of our DVDs.
NOTE: The NG DVD-R titles are not closed-captioned. We apologize for any inconvenience this limitation may cause.