WHEN the BBC launched The Real Marigold Hotel in 2016, some cynics may have initially seen it as an attempt to cash in on a successful movie. But in fact, it seems to have spawned a whole new subgenre, where TV bosses take a group of veteran celebs and pack them off on holiday together.

Sometimes, there's an added twist to the format - like Gone to Pot, the ITV series where Linda Robson, Pam St Clement, Christopher Biggins, John Fashanu and Bobby George travelled around America in a psychedelic bus to learn about the pros and cons of marijuana, or Last Laugh in Vegas, which saw the likes of Su Pollard and Bernie Clifton putting on a show - but usually the main draw is seeing the stars interact.

But what is that we find so entertaining about these series? Well, perhaps it's because seeing people enjoying themselves can be infectious - and the stars of Celebrity 5 Go Caravanning certainly seem to be having a good time.

Actress Sherrie Hewson admits she quickly bonded with her famous fellow travellers, telling What's On TV: "There was great camaraderie and some stories we told can't be televised!"

Over the past couple of weeks, we've seen the Benidorm star getting to know former Doctor Who Colin Baker, ex-EastEnder Todd Carty, legendary DJ Tony Blackburn and pop star Sonia, but this week there's a new recruit to their gang in the form of Brian Capron, who is best known for playing killer Richard Hillman in Coronation Street.

He hitches a ride as the caravanners meet at the Tamar Bridge before crossing from Devon into Cornwall - although Colin manages to get into a scrape before they even set off.

Once they are actually on the road, the gang get to swap anecdotes before arriving in Bodmin, where Brian's prior caravan experience comes in handy as he gives his new travelling companions a masterclass in awning arranging.

Tony then indulges in a slightly more adrenaline-fuelled activity as he takes a death defying leap from the edge of a disused quarry, while the other guys do a spot of ghost-hunting at Jamaica Inn.

But it seems for Sherrie, the most frightening element of the Cornish leg of their journey involved taking to the road on two wheels. She told What's On TV: "I haven't cycled for 25 years and in Cornwall they put me on a bike but I couldn't balance and got scared."

There's more trouble brewing when the heater fails in the girls' caravan, but maybe a cream tea will warm everyone up...

We can rest assured that any strife won't last for long as Sherrie has revealed that the caravanners are still keeping in touch via a WhatsApp group and were planning a meet up.

And if the news that this is the penultimate episode leaves you wondering where your next fix of holidaying celebs is coming from, ITV is currently showing Our Shirley Valentine Summer on Thursdays.

The Crystal Maze (C4, 8pm)

Richard Ayoade hosts the game show, inviting a team calling themselves the London Girls to take his golden hand and tackle a number of physical, skill, mystery and mental challenges. Although the presenter has a tendency to mock his own show, he is clearly aware that the people taking part take it very seriously - although this week's bunch prove rather rowdy and out-of-control. Can Richard keep them in line as they try to win the elusive crystals that will buy them time in the Crystal Dome at the end?

Gardeners' World (BBC2, 8pm)

Monty Don advises on plants for a late summer display, tackles his overgrown wildlife pond and shows which roses to prune now to ensure a repeat flowering before autumn. Frances Tophill travels to Birmingham where she proves that every space counts by transforming three tiny balconies into spaces full of colour and scent. Adam Frost shares ideas for planting around a seating area, while Nick Bailey continues his journey through the world of roses. Plus, the couple who have filled their Staffordshire garden with a collection of dierama, commonly known as angel's fishing rods.

Jane McDonald & Friends (C5, 9pm)

This week, the friends in question include Gilbert O'Sullivan, the hugely successful singer-songwriter who gave the world hits including Clair, Alone Again (Naturally) and Get Down. Jane will also be joined by Leee John and Any Dream Will Do winner-turned-West End and Holby City star Lee Mead. But while that's a decent line-up, regular viewers will already know that there's zero chance they'll manage to upstage the host. As well as proving her credentials as a travel companion on the Bafta-winning Cruising with Jane McDonald, the 'wonder from Wakefield' has also proved to be an engaging host on this entertainment series. So, even when she tries to cede the spotlight to her guests - and a few unsung heroes and audience members - she's still the star of the show.