Somehow or other I managed to watch some of it -- I remember the howling soundtrack over the scenes of standing rocks because it was the scariest shit ever. Anyway, it must have been available in the US at some point.
I just watched the entire thing off of Youtube. I didn't regret it. You just need to forgive the occasional loop holes near the middle that involve the smart adults not putting 1 and 1 together or suddenly not believing in someone bringing up a "this is some spooky shit" theory when just a second ago they all saw some really spooky shit happening. The ending was enh, but the ride was fun.
Ah the legacy of BBC and CBC to my childhood. I was the first kid I knew with cable way back when the Giants of Cable started.. when Nickelodeon didn't have programming of its own and it showed mostly imports... where I first saw The Tomorrow People and Tripods... along with Dangermouse and Count Duckula. It's like a forgotten legacy of cable.