The Real Marigold on Tour Season 4 is yet to be announced by BBC One

The group travel to the northern city of Chiang Mai, the cultural heart of the country, famous for its historic temples and laid back way of life. Once they've settled into their homestay, they venture out into the steamy 35 degrees heat.

Sheila Ferguson, Rustie Lee, Paul Nicholas and Dennis Taylor reunite to head on an adventure to the cold but beautiful country of Iceland, where they split their time between a small fishing village and the capital, Reykjavik.

In Hausavik the ladies visit a senior citizens centre - much to Sheila's trepidation. Meanwhile, Paul and Dennis join an all-male choir and end up singing to a huge audience in a canyon. The team then reunite to head out whale watching and are moved to tears by what they see.

After experiencing the peaceful, slow pace of life in Hausavik the foursome head six hours south to the capital, where the pensioners pastimes include aqua aerobics and gymnastics. Paul tries his hand at a handstand for the first time in many (many) years!

Sheila goes on a date with an Icelandic man and realises that, despite living thousands of miles apart, they have a lot in common.

Miriam Margoyles, Wayne Sleep, Bobby George and Jan Leeming reunite to head to the hot and vibrant city of Havana, Cuba, where life expectancy is high, food is rationed, and the way to travel is in iconic 50s cars.

The group stay in the capital Havana, and - after being wowed by the pink Cadillacs that pick them up from the airport - spend their first night learning to dance with the locals.

Later in the week Wayne visits a dance troupe and realises his classical training doesn't count for much when it comes to learning Cuban dance. But much to his joy he's invited to participate in the annual Cuban Carnival.

The group is staying in the capital of the Sichuan Province, Chengdu. A bustling city of over 14 million, all the group find the language barrier difficult and Miriam in particular struggles with the regional cuisine. A swim in a high-tech pool in one of the world's biggest buildings makes a bad situation worse, as Miriam discovers a modern China at odds with her memory of it from a trip 30 years ago.

After experiencing city life, the group opt for an overnight stay in a country retreat. A ride on a high speed Bullet Train takes them up into the mountains surrounding the city.

At a local sanctuary, home to the Giant Panda, a feeding session leads to an emotional moment for Miriam, while Rosemary can't quite understand what all the fuss is about. Back in Chengdu a final night at the Sichuan Opera gives the group an opportunity to reflect on their bewildering and dazzling time in China.

For the second part of their adventure the group go East to experience living like Japanese retirees. Miriam Margolyes, Wayne Sleep, Bobby George and Rosemary Shrager travel to Japan, which in 2015 had the second-highest life expectancy in the world - in search of the secrets to longevity.

In the historic city of Kyoto, they move into a homestay with 73 year-old twin sisters, Setsu and Fumie. Struggling with Japanese etiquette, Miriam soon learns that being loud and breaking wind in public doesn't go down well here.

Keen to live like locals the group start their day with an early morning keep fit class, called Radio Taiso. Broadcast nationwide, thousands of elderly residents take part in a free exercise class to keep everything ticking over.

Living a long life isn't just down to keeping fit - retirees in Japan also work well in to their 70s and 80s. Inspired by their hosts, Bobby and Miriam look for work at a job centre specifically geared to finding gainful employment for OAPs. For Bobby, this is the first job interview of his life, and for Miriam, it's a chance to reflect on what she'd still like to achieve. The pair are employed to work in a gift shop, while Rosemary and Wayne get a job in one of the busiest noodle bars in Kyoto.

Another pastime enjoyed by most senior citizens is a long soak in the hot springs dotted around the country. But unlike the spas Miriam and Rosemary are used to back home, this therapeutic remedy is traditionally done naked with everyone else bathing with you. Horrified at the thought, the ladies have to decide just how authentic they want their trip to be.

Inspired by the Japanese attitudes to keeping the body and brain active, eating the right food and finding employment, the group are heading home with lessons learned about how to live out their golden years.

In this episode they travel to Florida, one of the retirement capitals of the world, with low taxes and yearlong warm weather. Visiting two different retirement villages at either end of the scale, the group join the millions of Americans who are seeing out their golden years in Florida's vast gated communities - a new kind of suburbia for the over 55s, with healthy activities, 24-hour security and no children.

The famous four start their trip north of Orlando in Oak Run, an affordable community for 7,000 residents enjoying daily exercise, hundreds of clubs and weekly bingo. Keen to know the locals, Wayne decides to start a dance class, Rosemary throws a party for the neighbours, and Miriam takes Bobby to the local gun shop, to learn that despite living in fortressed ‘Leisurevilles', retirees are in fact their best customers.

The group's second destination is an hour north of Miami. The Polo Club, marketed as the height of retired living and home to some of the richest senior citizens in the states, charges $85k per year to be a member. But arriving at their new luxury home soon divides opinion in the group, and their experience of what many residents here consider to be the idyllic lifestyle is not for everyone.

Barely an hour in to their stay a heated exchange ensues and Miriam learns that talking politics and real life with a bunch of blissfully happy retirees is never a good idea. Meanwhile, Rosemary is intrigued to know how the Polo Club members appear to look so young, and she decides to visit a local cosmetic surgeon in a bid to hold back the years.