Rocky Mountain PBS
Colorado Science: Researchers discover secret to Castle Rock's longevity
Denver Museum of Nature and Science researchers found that Castle Rock’s durability is due microscopic amounts of the colorful gemstone opal.
Season 1 Episode 102 | 50m 52s | CC
In the countryside of County Clare, Ireland, is the Burren, a mysterious place unlike anywhere else, with deep caves, a stony landscape, and ancient dolmens, ring forts, and castles. The two-part documentary series The Burren: Heart of Stone, narrated by award-winning Irish actor Brendan Gleeson, unveils the secrets hidden in the stones of this dramatic wind-swept countryside.