Just watched it myself - excellent stuff! Been to Gunnerkeld which is mentioned as part of the megalithic complex.

Fascinating indeed but also sad to think what has been lost, particularly in such a relatively remote area where one might have expected more to have survived.

Shap has always fascinated me. There are LOADS of toppled megaliths lying between the Northbound/ Southbound lanes of the M6 from Gunnerkeld right down to the Services at Tebay. Plus plenty more on either side. Looks like some carnage occurred,
https://maps.app.goo.gl/ygGwFzpgDoc4brDX7
Last time (and the first time) I stopped at Gunnerkeld was 13 years ago this month en-route back from North Wales. Always loved seeing Gunnerkeld from Citylink buses to London or from my various cars' windows as I drove by over the decades.

I watched that video a few days ago. I have always been awaiting a "proper" fully-funded, yop-of-the-line C4, BBC or somesuch documentary. But none has ever appeared. Must be too busy with their diversity work or sumhin.

I walked it end to end about two years ago. Beautiful landscape and cracking stones.