Penelope Keith's Hidden Villages (Channel 4, 8pm)

IN the classic sitcom The Good Life, Penelope Keith's snooty Margo wasn't impressed by Tom and Barbara's efforts to bring rural life, including pigs and chickens, into her corner of Surbiton.

In real life, the actress has been a proud Surrey villager for the best part of 40 years. And for the past two of them, she has been leading a TV mission to show townies what life in a small community is really like. The actress has spoken about some of the issues facing rural areas, including a lack of public transport, the closure of pubs and shops, and rising house prices that are driving out the locals. But she's also been keen to point out that many of these communities are adapting to the 21st Century, with a new generation determined to keep old traditions alive.

"One does tend to get this idea that it's a load of old codgers tottering around, like me, with straw in their hair, but it's not, a lot of them are thriving," she's said.

There's certainly no shortage of villages for Keith to explore – she's already notched up 62 in 18 counties, and she's back using the Batsford Guides, which were published from the 1930s onwards and offer a snapshot of rural life – and a way of gauging how much has changed.

In this series we'll see the dales and moors of North Yorkshire, the lochs and islands of Argyll & Bute, and the Welsh retreat of Pembrokeshire, but she begins in the place that many people most associate with "chocolate box" villages – the Cotswolds.

The region's money originally came from sheep, wool and weaving, but now it's home to a new kind of riches. Keith's friend Jilly Cooper (who has been a Cotswold villager since 1982), explains why celebrities are drawn there, and which famous faces have been spotted in the vicinity. But the presenter also discovers that the Cotswolds are far from being just a sleepy retreat for rich city types – the villages also have a history of creativity. There's a tour of Kelmscott, the spiritual home of Arts and Crafts, and Slad, which provided the setting for Laurie Lee's much-loved Cider with Rosie.

Keith also heads to Down Ampney to learn how heroines helped 100,000 injured soldiers, before discovering that some country retreats include beer delivered by horse-drawn dray and picture perfect village fetes.

Coast: The Great Guide (BBC2, regions vary)

NEW series. Tessa Dunlop and Neil Oliver present the ultimate guide to the Cornish Coast, from the River Tamar to Tintagel Castle, as they discover what makes the stretch so unique. As well as selecting some of the best Coast stories from the past 10 years, Tessa takes a ride on a variety of boats to learn the untold secrets of the Cornish shores. The presenters go line fishing with a local Looe fisherman, explore serpentine rock on The Lizard with a leading geologist, uncover a story of tragedy at sea, and find out what it is like to live in the storm-hit harbour of Porthleven.

Grand Designs (C4, 9pm)

KEVIN McCloud is back for a new series, and he begins by meeting a couple who have taken on a project that's hugely ambitious, even by Grand Designs standards. Plumber Jon Martin and ceramicist Noreen Jaafar have acquired an overgrown, neglected half acre of land in the heart of a Gloucestershire town. The fact that its home to 27 protected trees would put off many developers, but for the couple it was all part of the attraction as they intend to build a modern tree house. The property will be set up in the branches, with stilts screwed into the earth and balconies that provide spectacular views. However, building it is not going to be easy, especially on a tight budget. After two years of trying to turn their dream into a reality, can an exhausted Jon and Noreen finally finish the project?