The first episode is the Netherlands, where they try out the sport of canal jumping, before the pair don Lycra for a spot of velodrome track cycling alongside a world champion, and take on the world's tallest freestanding climbing wall.

Bradley and Barney continue their European adventure in Germany. They head to the city of Frankfurt, where Brad is pushed to the edge, literally, as he attempts to abseil down the side of a building, facing forwards. The boys also make a stop at a bratwurst-themed hotel and soak up some local Bavarian culture when they have a go at finger wrestling. The pair finish off their time in Germany with a wet and wild adventure in the mountains.

The actor and his son continue their European adventure in Switzerland, where they take a ride on a mountain rollercoaster before exercising their vocal chords when they try the Swiss tradition of yodelling. The following day, Barney arranges a unique way for them to enjoy some local cheese, and then drive to the Contra Dam, where Barney reveals they are about to attempt one of James Bond's most famous stunts.

The actor and his son continue their European adventure in Slovenia, where Brad's passion for bikes gives Barney an excuse to take his dad motocross racing. They meet a beekeeper and are treated to some unusual honey therapies, before joining the national Quidditch team in the capital Ljubljana, and having a go at the notoriously dangerous sport of ski jumping.

The duo continue their European adventure in Italy, starting in the picturesque Lake Garda, where Barney surprises his dad by explaining they'll be running off the top of Monte Baldo and paragliding over the lake below. The next day Bradley is treated to a hair-raising ride in a Formula 1 speed boat, before the Walshes are invited to the home of opera superstar Andrea Bocelli.

The duo embark on the final leg of their European road trip as they explore more of Italy, engaging in gladiatorial combat in Rome, before continuing south and making a stop to soak up the views from a sky-high zipwire. As they reach their final stop on the Amalfi Coast, they get the chance to swim in the sea, but they'll have to dive in from a cliff.

Bradley and Barney begin their second series in Florida, where they visit the Palm Beach International Raceway and the home of the author Key West, and get close up to sharks.

The duo head to the Great Smoky Mountains on the Tennessee-North Carolina border and go canoeing. After a swig of whiskey, they experience clog dancing and chopping wood with the aid of competitive lumberjacks.

For the next leg of their journey, Bradley and Barney visit the Red River Gorge in Kentucky, before heading to the supposedly haunted Poasttown Elementary School in Middletown, Ohio. The next day, they travel to Louisville, birthplace of legendary boxer Muhammad Ali, where they follow in his footsteps by sparring at the local boxing gym. At the end of a long day, Barney rewards his dad with a well-earned meal at a KFC restaurant in Kentucky - the home state of the chain's founder Colonel Harland Sanders.

Bradley and Barney arrive in Ohio, where they head for Dayton - the birthplace of aviation - before the pair attend a local rodeo later that evening. Brad soon realises that they are not just there to spectate on the sport, they are also expected to take part. However, a nasty fall from an angry bull means Brad spends the rest of the night in hospital.

Bradley is on the mend following his rodeo injury and determined to get back behind the wheel of the RV. As the pair continue on their journey, Barney is thrilled to be celebrating his birthday with a trip to the iconic Niagara Falls. Later, Bradley and Barney take the RV on a small cargo ferry as they head to Vermont. Here, the pair have a go at ice climbing, which proves treacherous for them and the crew, before a spot of dog sledding through the frozen wilderness and an inevitable race through the forests.

On the final leg of their journey, the pair continue through the snow to New Hampshire. Here, they meet rally-driving champion Tim O'Neil who gives them a crash course in driving in the ice and snow before they take on an intense time trial. The pair travel on to Maine, where they take part in some wilderness training, before bidding farewell to the RV and heading out into the extremely choppy seas for some lobster fishing. Before heading home, the pair look back on some of their favourite moments from the trip.

The actor and his 20-year-old son Barney hit the road together, travelling more than 2,000 miles from Los Angeles to New Orleans. The pair begin their journey in Los Angeles, and head down to Muscle Beach to lift weights, before taking part in a game of volleyball. The following day, Bradley is terrified to hear that the agenda involves a 14,000ft skydive.

Actor Bradley Walsh and his 20-year-old son Barney hit the road together, travelling more than 2,000 miles from Los Angeles to New Orleans. In the second leg of their journey, the pair leave the city of Los Angeles behind and make their way down the famous Route 66 to the southwestern state of Arizona. Here, they ride through a deserted ghost town, before the father and son reach Lake Havasu City, where Barney has arranged for them to try jet-skiing. Finally, they attend a Cowboy College, where they learn to become real-life horsemen.

The actor and his son Barney arrive in Texas, where they enjoy driving around in tanks, experience space travel in a centrifuge and hear campfire tales about UFOs. First up, the pair undertake some centrifuge training, which is used to prepare astronauts for the crushing gravitational forces produced at take-off from the extreme exhilaration. They also head to the outskirts of Houston to meet some UFO enthusiasts who investigate claimed sightings of extra-terrestrials and are gripped by stories of spaceships blocking roads and people being taken by aliens for experiments.

In episode four, Bradley and Barney travel to New Orleans in Louisiana, the fourth and final US State of their trip. Sitting on the mighty Mississippi, New Orleans is known for its vibrant nightlife, live music and laidback attitude. Bradley and Barney drive across the border in their RV and head straight for the city’s most famous mode of transport – the steamboat.

The actor and his son Barney reflect on their travels around America, picking their favourite moments and revealing previously unaired footage of their adventures. Armed with popcorn and refreshments, the Walshes watch back everything from additional unseen footage to moments they captured on their phones, behind-the- scenes clips with the crew and compilations of their road-trip antics. These include more sing-along bangers from their playlist, Brad's jokes, their favourite snacks, as well as quizzes and games they played to pass the time

Bradley and Barney Walsh will be up to snow good as they take their famous RV across the sea to the magical island of Iceland, for a special bumper Christmas episode of the beloved father and son travel show. The Walsh boys will test themselves to frosty new limits in the country of volcanoes, glaciers and breath-taking landscapes, finding Christmas joy and terrifying challenges in equal measure. That’s why Dads go to Iceland! By the end of all their festive frolics, will they discover the most valuable Christmas experience is spending time with the people we love, or will they be left bickering about their frostbite?