This week two new National Geographic Television specials, produced exclusively for PBS, follow the adventures of explorers who set out to reach the forbidden Kingdom of Mustang — off-limits to Westerners for 50 years — and the unseen treasures these lost caves contain.

In Secrets of Shangri-La, premiering Thursday, November 19 at 10 p.m., seven-time Everest summiter Pete Athans and a team of internationally renowned climbers and explorers journey to Mustang, joining forces with archaeologists, anthropologists and art historians to rescue rare Tibetan texts from crumbling, long-hidden caves before looters reach them. When a political group from a nearby village tries to stop them, an intriguing set of events ensues involving the King of Mustang, the highest lama of the land, and even the local divinities believed to inhabit the area.

Watch a preview:

In Lost Cave Temples of the Himalaya, premiering Saturday, November 21 at 9 p.m. on WLIW21 & WLIW World, follow Pete Athans and big-wall climber Renan Ozturk as they take on the dangerous job of climbing into the crumbling caves for the first time in modern history. Their goals are to get inside the inaccessible cave cities, unoccupied for hundreds — if not thousands — of years, to document what’s inside and to search for nine legendary cave temples called “kabum.” What they find goes far beyond their expectations, rocking the Himalayan world and rewriting the history of this remote and mystical region. The treasures include a 55-panel painted mural and piles of old Tibetan manuscript folios, some printed in silver and gold. Each vertical move into a cave opening is a step into the unknown.

Watch a preview: