CatM
Moderator
I'm surprised no-one has mentioned this already, as it was apparently made in 2012 and I think it's been on Prime for a while, but I couldn't find anything using the search function. Anyhoo....
An interesting documentary about the search for the Timavo river near Trieste, Italy, which has continued for almost 200 years.
Following on from that, I also just came across this article, published last week:
www.intrieste.com
Watch River at the Centre of the Earth | Prime Video
Marco digs and squeezes through dark Italian caves hundreds of metres underground. He is continuing an amateur 200 year search for the mysterious river Reka. Death lies at every corner - falling stalactites, CO2 poisoning. It's a tale of generations fixated with one deep hole in their backyard...
www.amazon.co.uk
An interesting documentary about the search for the Timavo river near Trieste, Italy, which has continued for almost 200 years.
Following on from that, I also just came across this article, published last week:

Huge Cave Discovered in the Depths of Trieste's Underground Timavo River - InTrieste
Reading Time: 5 minutes by Alessandra Ressa Trieste’s Timavo river has unveiled yet another wonder in the depths of its mysterious underground path. 160 meters long, 50 meters wide and 60 meters high, the new cave, connected to the 350-meter deep Trebiciano Abyss by an underground lake and a...
