Following the successful natural history series Wales: Land of the Wild and Land of the Wild: After Dark, a brand new documentary reveals the secrets of Welsh wildlife and features jellyfish, catshark and the rare sand lizard, with some of the spectacular wildlife filming done in Pembrokeshire.

Narrated by Michael Sheen, Land of the Wild: Secrets is an extraordinary journey using innovative camera technology to uncover the hidden worlds of Welsh wildlife.

This is a story of survival and romance set against the backdrop of some of Wales’ most breath-taking landscapes; from the red grouse on the dramatic mountainous uplands, to the illusive catshark, master of the Celtic Deep, and everything in between.

Speaking in the documentary, Michael Sheen said; “This is an epic journey, following wild waterways; from the highest mountains to the Celtic Deep. Cutting edge technology reveals hidden secrets and brings us a little closer to the land of the wild”.

The documentary showcases the wild beauty of the coastlines of Pembrokeshire and the latest underwater cameras unveil the wonders of the Celtic Deep. The undisclosed life of the barrel jellyfish which inhabit these waters around Pembrokeshire is revealed. The programme also follows the secretive catshark, a predator that is top of the food chain in these waters, who is on the hunt for a mate. This is a furtive event which is rarely witnessed.

You can watch Land of the Wild: Secrets on BBC1 Wales on Thursday, March 25 at 8pm.