TV Guide BBC Four Wednesday

The former steeplejack explores the achievements of Britain's civil engineering pioneers, visiting the Channel Tunnel, Humber Bridge and Pontcysyllte Aqueduct. He also has a go at legging a narrowboat through a canal tunnel in Dudley in the West Midlands

Comedian and actress Nina Wadia unwinds in the spring setting of Swaledale in the Yorkshire Dales National Park, where she reflects on personal family challenges, including the loss of her parents. Nina also meets an ornithologist who shows her some of the rarer bird species found in the area, and tests her skills in a new language when bumping into a village elder who speaks 'Swardle', the historic local dialect

Wildlife documentary observing Professor David Scheel as he takes an octopus into his home to learn about its intelligence, and the extraordinary relationship he and his daughter develop with the creature. Named Heidi, the octopus is seen unravelling puzzles, recognising individual humans and even watching TV with the family. The film also looks at the remarkable behaviour of other octopuses around the world, from those that can change their colour and texture in a split second to the octopus that carries around its own coconut shell to hide in

Following a 30 year archaeological, geological and artistic adventure as scientists endeavour to understand and conserve the art of the Chauvet cave. Hidden deep inside France's Gorges de l'Ardèche, the cave was revealed to the modern world for the very first time in 1994. It has over 1,000 paintings adorning its walls and scientists immediately recognised the importance of the discovery

Miles urges Delilah to have an HIV test and Egg, deeply embarrassed at having caused a scene, seeks advice from Warren's therapist. Anna worries she isn't getting enough work at the chambers and hits on the bright idea of using her feminine charms to drum up business

Anna organises a special dinner to fan the flickering flame of romance between Milly and Egg, while Miles gets short shrift from his father. Meanwhile, Warren fears blabbermouth cousin Kira will discover he's gay and spill the beans to the rest of the family. Jason Hughes, Jack Davenport and Daniela Nardini star

An insight into the development of forensic science as a way of catching murderers over the past 200 years, charting the scientific breakthroughs that have changed the course of justice. Surgeon and writer Gabriel Weston begins by looking at the difficulty of identifying the body in a murder case, from charred bones to bodies completely dissolved in acid. She focuses on the use of teeth and bite marks to identify a victim or killer, traces the uses of insects to pinpoint the time of death, and meets the geneticist who pioneered the technique of DNA profiling