What on Earth? - Full Series Information, Trailer & IMDb Reviews
What on Earth? Season 11 Episode 4

Episode Title: Mystery of the Welsh Mine
Genre:
Documentary
Countries:
,
Airing Date: July 13, 2022
Runtime:60 mins
IMDb Rating:

Watch What on Earth? Season 11 Episode 4 online — it may be available on legal streaming platforms such as YouTube, Netflix, Prime Video, Hulu, Disney+, and others.
Satellite images capture monumental ruins surrounded by bizarre feather-shaped structures on a Welsh mountaintop; experts investigate a hidden tunnel containing the remains of an abandoned slate mine with an exploitative and deadly past.