Scotland's Lost Worlds. Ben journeys from Stroma, inhabited 1,000 years ago, to Swona, its first inhabitants being the Vikings and then to the towering prehistoric cliffs of St Kilda, the most remote of Scotland's islands. 2/3. Adventurer Ben Fogle travels to remote corners of the world and uncovers what caused people to leave these areas, and witnesses new efforts to revitalise the islands that time forgot.

Maths. Quiz show in which the aim is to be interesting. Stephen Fry masters the maths with Sandi Toksvig, Aisling Bea, Susan Calman and Alan Davies. 5/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Marriage and Mating. Quiz show in which the aim is to be interesting. Stephen Fry makes merry with marriage and mating with Jo Brand, Greg Davies, Bill Bailey and Alan Davies. 6/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Eltham Palace. The Roadshow is in the elegant surroundings of Eltham Palace in south London, once the boyhood home of Henry VIII. 4/26. Experts invite the public to bring along their antiques for examination. Some find their 'bric-a-brac' to be worth much more than they ever suspected.

Series 26, Episode 18. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of. 18/55. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of.

Secrets, Spies & Sleuths. Sandi Toksvig uncovers a stash of secrets with Alan Davies, James Acaster, Daliso Chaponda and Cariad Lloyd. 2/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Buses. The red double-decker bus is a global icon. They carry millions of passengers every day across the capital, and Gregg Wallace has special access to a bus-building factory in Scarborough, Yorkshire. 3/9. Gregg Wallace, Cherry Healey and Ruth Goodman get exclusive access to some of the largest factories in the world to reveal the secrets behind the epic-scale production of our favourite products.

Pastry Week. It's Pastry Week and the bakers tackle choux pastry doughnuts and a tricky Turkish technical, before creating a savoury, delicately designed showstopping pastry pie packed full of flavour. 6/10. Twelve enthusiastic contestants face three challenges a week as they take part in a competition to determine which of them is Britain's best amateur baker.

West Highlands. The West Highland Line wends its way from Glasgow to the Isle of Skye, taking in Loch Lomond, windswept Rannoch Moor and Corrour - Britain's highest railway station. 3/6. Enjoy six very individual and stunningly beautiful train journeys from around the world. On each one we'll meet the people who work and live along the special rail line in six different countries.

Bavaria. A trip through the Bavarian Alps, with stopping points including a former Olympic village, Germany's highest mountain, and a quick tipple with a beer-brewing monk. 4/6. Enjoy six very individual and stunningly beautiful train journeys from around the world. On each one we'll meet the people who work and live along the special rail line in six different countries.

Series 26, Episode 18. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of. 18/55. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of.

Secrets, Spies & Sleuths. Sandi Toksvig uncovers a stash of secrets with Alan Davies, James Acaster, Daliso Chaponda and Cariad Lloyd. 2/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Pastry Week. It's Pastry Week and the bakers tackle choux pastry doughnuts and a tricky Turkish technical, before creating a savoury, delicately designed showstopping pastry pie packed full of flavour. 6/10. Twelve enthusiastic contestants face three challenges a week as they take part in a competition to determine which of them is Britain's best amateur baker.

Helmingham Hall 3. Fiona Bruce and the team return to Helmingham Hall in Suffolk. Treasures include a dazzling sapphire ring and a Girl Guide sketch by Robert Baden-Powell. 21/26. Experts invite the public to bring along their antiques for examination. Some find their 'bric-a-brac' to be worth much more than they ever suspected.

Buses. The red double-decker bus is a global icon. They carry millions of passengers every day across the capital, and Gregg Wallace has special access to a bus-building factory in Scarborough, Yorkshire. 3/9. Gregg Wallace, Cherry Healey and Ruth Goodman get exclusive access to some of the largest factories in the world to reveal the secrets behind the epic-scale production of our favourite products.

Middle Muddle. Quiz show in which the aim is to be interesting. Stephen Fry muddles through the middle show of the middle series of QI with Aisling Bea, Danny Bhoy, Jimmy Carr and Alan Davies. 7/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Merriment. Quiz show in which the aim is to be interesting. Stephen Fry conjures up some seasonal merriment with Jenny Eclair, Johnny Vegas, Bill Bailey and Alan Davies. 8/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

York to Edinburgh. Escape with us aboard the magnificent steam train Tornado as its coupled up with 13 luxury vintage carriages on a 6 hour journey through Yorkshire, to Northumbria and the Borders. 8/10. Enjoy six very individual and stunningly beautiful train journeys from around the world. On each one we'll meet the people who work and live along the special rail line in six different countries.

Smartphone. With rare access to electronics giant Samsung, Hannah uncovers the technological game changers that have made the smartphone a reality. 3/6. Mathematician and television presenter Hannah Fry hosts a series revealing the miraculous technologies that define the modern world.

Erddig 1. Fiona Bruce and the team are at Erddig, north Wales, for this week's Roadshow. Items include a dazzling ring worn by the owner's grandmother on the Titanic. 5/26. Experts invite the public to bring along their antiques for examination. Some find their 'bric-a-brac' to be worth much more than they ever suspected.

Series 3, Episode 6. Judges May Martin and Patrick Grant must decide who has done enough to be crowned Britain's best amateur sewer, with some final challenges. 6/6. Amateur sewers take on challenges as they compete to be Britain's best home sewer. Their creations are judged by Savile Row's Patrick Grant and sewing expert May Martin.

United. Sandi Toksvig, Nabil Abdulrashid, Bill Bailey, Victoria Coren Mitchell and Alan Davies are all in it together for this United episode. 3/14. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Unsavoury. Join Sandi Toksvig for a thoroughly Unsavoury episode of QI, with Gyles Brandreth, Judi Love, Kiri Pritchard-McLean, and Alan Davies. 4/14. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Series 26, Episode 45. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of. 45/55. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of.

Series 14, Episode 5. Jimmy Carr hosts the comedy game show mash-up. Roisin Conaty and Kiri Pritchard-McLean take on Jon Richardson and Rob Beckett. With Huge Davies, Joe Wilkinson, Susie Dent and Rachel Riley. 5/13. Combining two of viewers' favourite shows means that viewers get to play along, a bonus for both quiz and comedy fans alike. Jimmy Carr hosts the famous words and numbers quiz, plus etymologist Susie Dent on the letters, and maths whizz Rachel Riley on the numbers.

Episode 2. A behind-the-scenes look at the series that explores the most successful animal group on Earth, from the tiny Etruscan shrew to the largest mammal in existence - the blue whale. 2/6. A behind-the-scenes look at the series that explores the most successful animal group on Earth, from the tiny Etruscan shrew to the largest mammal in existence - the blue whale.

Bath Bombs. Gregg Wallace visits the Lush factory in Dorset to learn how an astonishing 14 million bath bombs are produced every year. Plus, Cherry Healey learns how taking a hot bath can provide benefits. 6/10. Gregg Wallace, Cherry Healey and Ruth Goodman get exclusive access to some of the largest factories in the world to reveal the secrets behind the epic-scale production of our favourite products.

Morocco. Ben returns to Morocco to meet Karen again, who had built a guest house and artists' retreat in this inhospitable location. 2/9. Adventurer Ben Fogle revisits some of people from the first five series of 'Where the Wild Men Are' to find out how they are getting on with their new, remote lives.

Pulled from the Darkness. As Alaskans enter a new dawn in the Arctic winter, they must adapt to the changing landscape if they are to survive. 1/20. The brutal Alaskan winter dominates life for the hardy characters in this awe-inspiring series.

Middle Muddle. Quiz show in which the aim is to be interesting. Stephen Fry muddles through the middle show of the middle series of QI with Aisling Bea, Danny Bhoy, Jimmy Carr and Alan Davies. 7/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Merriment. Quiz show in which the aim is to be interesting. Stephen Fry conjures up some seasonal merriment with Jenny Eclair, Johnny Vegas, Bill Bailey and Alan Davies. 8/16. Panel game hosted in which celebrity guests have to answer questions, avoiding repeating common misconceptions and urban myths.

Series 26, Episode 18. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of. 18/55. Quiz show in which contestants try to score as few points as possible by coming up with the answers that no-one else can think of.

Series 14, Episode 5. Jimmy Carr hosts the comedy game show mash-up. Roisin Conaty and Kiri Pritchard-McLean take on Jon Richardson and Rob Beckett. With Huge Davies, Joe Wilkinson, Susie Dent and Rachel Riley. 5/13. Combining two of viewers' favourite shows means that viewers get to play along, a bonus for both quiz and comedy fans alike. Jimmy Carr hosts the famous words and numbers quiz, plus etymologist Susie Dent on the letters, and maths whizz Rachel Riley on the numbers.

Bath Bombs. Gregg Wallace visits the Lush factory in Dorset to learn how an astonishing 14 million bath bombs are produced every year. Plus, Cherry Healey learns how taking a hot bath can provide benefits. 6/10. Gregg Wallace, Cherry Healey and Ruth Goodman get exclusive access to some of the largest factories in the world to reveal the secrets behind the epic-scale production of our favourite products.