YONKS ago, or in 1873 to be more accurate, Isabella Bird, an English woman, crossed the Rockies on her own and wrote a book called A Lady’s Life in the Rocky Mountains.

Bird of course was deemed to be an inspirational figure, having survived the journey during which she defied weather, befriended outlaws, climbed mountains and faced grizzly bears.

Now, three celebrities, Scary Spice Mel Brown, Inbetweeners actor Emily Atack and comedian Ruby Wax have taken on that same journey in Trailblazers: A Rocky Mountain Road Trip (BBC2, Monday) albeit supported with sat-nav, mobile phones, crew support, catering trucks, personal assistants, make-up assistants and film directors.

But there is a point, a focus to this show, other than to promote the careers of fading performers. The production company behind Gordon, Gino and Fred’s telly adventuring now see Bird’s Wyoming travelogue as “an inspiration”, a chance for the three new amigos to pay homage to this forgotten pioneer, whom they hadn’t heard of.

Yet, should you think this television adventure sounds a little contrived and indeed perhaps risks ridiculing of Ms Bird’s endeavours, bear in mind that the threesome does indulge in rock climbing, fly fishing and – perhaps that most demanding feat of all – remaining upbeat and funny and vulnerable, without falling off the rock that is believability into abject silliness.

And even though Isabella Bird did once fight off grizzlies, remember that Scary Spice once had to contend with Ginger.

Still on the subject of scary people, did we ever truly realise what an awful human being Hugh Hefner was? The Secrets of Playboy, (Channel 4, Monday) puts us right.

The owner of the Playboy Mansion, the pipe-puffing self-styled love god who inspired a sexual revolution – and a man who, he claimed, thousands of young women came to adore – rarely discarded his silk dressing gown.

But the truth is a little less shiny. This 12-part series suggests the Playboy Mansion, far from being a mini-paradise, was in fact a cult centre, and Hefner the leader who exploited and debased women.

As one former Playmate says: “At the mansion, the indoctrination, I feel, starts almost immediately when you’re there, and you start hearing about how wonderful Hef is from his circle of his friends.”

Another adds: “So, in the beginning, Hef is what you would now call a love bomber.

“He’s somebody who tells you ‘I love you’ almost immediately.”

This series is stunning in its understanding of how Hugh Hefner was able to create his own world, a cult, in which he set all the rules.

But away from the world of sexual predation, for those who wish to understand how we “think, feel and act” about sex, a rather bold new documentary series arrives, which could prove to be both enlightening – and rather shocking.

Planet Sex with Cara Delevingne (BBC3, Thursday, 10pm) is not a show to watch with your parents/children/anyone who knows you.

It’s fronted by supermodel Delevingne, and the thick-browed occasional actor now performs the role of sex guru and is prepared to investigate the taboos and traditions of the likes of gender identity, “ethical” porn, and poly relationships (which you may assume is for the birds, but apparently it isn’t at all).

In this new series – each episode is an hour long – she speaks to an array of sex experts and even signs up for a class in female masturbation, all in a bid to garner different perspectives on human sexuality.

No-one can say the model isn’t prepared to go where few presenters have gone before.

Have we been to Aberdeen before, in terms of a network Scottish crime series?

I don’t think so. Granite Harbour, (BBC Scotland, Friday) takes us to the north-east and it’s great to see the multi-talented Scot, Hannah Donaldson, achieve network recognition in this new police drama.

Perhaps surprisingly, the plot follows the adventures of a Jamaican constable Davis Lindo (Romario Simpson) who finds himself based in Aberdeen, via a stint with the Royal Military Police.

But the wind and the cold and the Doric aren’t the only challenges he faces. Before you can say “hypothermia”, Lindo has to investigate the death of an oil industry boss (the formidable Ron Donachie) and is paired with a no-nonsense, incredibly streetwise superior officer, DCI Lara Bartlett (Donaldson).

If you like trying to work out the mystery of the death rather than spend too much time thinking of how or why a Jamaican police hopeful would find himself as the fish-out-of-water character in a fishing town, then this series could be for you.