Mysteries of...

The first in a series of documentaries exploring places with a mysterious past through a combination of history, archaeology and mythology, starting with Stonehenge. The programme takes an extensive look at the site's origins, from tales of Merlin to African giants in Ireland, and traces how prehistoric peoples harnessed the power of the sun to make profound statements about the cycle of life and death. It also explores the recent revelation that one of the sacred stones may have originated over 1000 kilometres away on Orkney.

There are certain places in the world that hold a powerful grip over the collective imagination. Places where mysteries and myths abound. This new series explores the secrets behind three iconic sites and phenomena, continuing with a warm-hearted and quirky feature-length documentary on Loch Ness, which dives into the enduring mystery of the Loch Ness monster and explores the history, folklore and science of - and our unwavering fascination with - the world's most famous (but largely quite shy) monster. Believers, sceptics, tourists and locals contribute - including a passionate Nessie hunter who believes he has the first audio recording of the monster, and an academic who considers the psychology behind these strange sightings. And there's a tour around the globe and similar legends of lake monsters. In the end though, what or who is Nessie? Sea serpent? Prehistoric plesiosaur? Repetitive hoax?

This feature-length documentary dives into sinkholes, a terrifying phenomenon that has plagued humanity for thousands of years. Sinkholes form suddenly and without warning. The film explores sinkholes high up in the mountains of south west China and sinkholes hundreds of metres underwater in the Gulf of Mexico. Laura Gerber nearly drowned in a water-logged sinkhole. Matt Pritchard was forced to watch a chasm slowly tear his home apart. But how do sinkholes form, some being natural and others human-induced? In Florida's infamous 'Sinkhole Alley', with over 20,000 recorded incidents, and in Guatemala City, where an epic 20-metre sinkhole swallowed up a three-storey factory, destructive sinkhole secrets are revealed. But sinkholes don't just bring destruction. Cutting-edge technology reveals living environments deep within sinkholes. Cavers and divers pursue exhilarating archaeological expeditions 80 metres deep, unearthing hidden worlds dating from ancient Rome and the Maya civilisation.