The teams set off from Greenwich. They must pass through five checkpoints to reach their final destination. First up: the ancient city of Delphi.

The five teams head to their next checkpoint - Baku in Azerbaijan - a journey that will see them leave behind the familiarity of the West for the exotic and unknown of the East.

The four remaining teams leave Azerbaijan and head across the deserts, mountains and Silk Road cities of Central Asia in the third leg of the challenge. Along the way, they meet a stuntman with a high-octane car, get the chance to watch a grisly 13th-century Kazakh sport played between horse riders and using the carcass of a dead goat, and brave a storm on the Caspian sea.

The global travel series reaches another level this week as the four remaining teams enter the People’s Republic of China. After nearly a month on the road together, relationships are coming under increasing pressure in what is the most challenging leg of the race to date. With vast distances to cover to the checkpoint - the ancient village of Huangyao - budgets are running low and emotions are high.

It is the penultimate leg of BBC Two’s unrivalled travel series, that has taken viewers on a journey through the wilds of Kazakhstan to ancient villages in China. This leg sees the remaining four teams head through the dense forests and bustling metropolises of Cambodia and Vietnam, and the final checkpoint before Singapore – the island paradise of Koh Rong.

The teams face the final leg of their journey, travelling 1500 miles down the Malaysian Peninsula to Singapore. However, seven weeks on the road is starting to take its toll. Josh and Felix are reliant on the kindness of strangers, Natalie and Shameema make a desperate gamble, Tony collapses with back pain, and Darron is forced to face his fear of dogs. Last in the series.

In a frenetic race across the world, travellers can choose any route they like - but no flights or phones are allowed. On the trip of a lifetime, which pair will finish first?

The five intrepid teams reunite in London to look back at their 51-day thrilling adventure through some of the most beautiful, populous and remote places on the planet.

The five pairs are challenged to race from the island checkpoint of Sanya to the mysterious Shangri-La – a city sitting on the edge of the Tibetan plateau towards the foothills of the Himalayas.

After reaching Shangri-La in China, the teams discover where they’re headed next – one of the world’s oldest living cities, Varanasi.

After racing nearly 13,000 kilometres over seven weeks through China, Nepal and India, the four teams are about to embark on the final leg of the race.

The five teams reunite for the first time to reveal fascinating insights into their different strategies and individual experiences - from their highest highs to their lowest lows.

With a thrilling third series of the Bafta-winning adventure now over, our five pairs meet up again to reflect on the adventure of a lifetime. Season Finale

The teams race to reach the second checkpoint – Sanya, one of China's most southerly cities. As well as choosing the best route to get there, they have a typhoon to contend with.

With over two thirds of the race completed, and almost 10,000km travelled, four teams have successfully made it to the fifth checkpoint, McLeod Ganj.

Six months after undertaking the race of a lifetime, the five intrepid pairs meet for the first time since returning home in this reunion episode.

The race to St John’s continues as the five teams leave Haida Gwaii and head into the heart of the Yukon towards the second checkpoint, the former gold rush boom town Dawson City.

The teams head for Lake Huron, a 3,000-kilometre journey, but the pairs only have one way out of Churchill – a noisy overnight train south.

The race to Lombok is well underway and less than five hours separate the teams. Leaving Nara City, they must cross their first border into South Korea to reach the second checkpoint in Sokcho.

The teams are starting from the third checkpoint in Phnom Penh, Cambodia, and must travel 1,400 kilometres through Thailand, one of the most visited countries in the world.

The teams must navigate the full length of Thailand to reach the next checkpoint - Koh Phi Phi - an archipelago of islands immortalised by the Hollywood blockbuster movie The Beach.

After the tranquillity of the islands of Koh Phi Phi, the teams now face a giant leap into the unknown, leaving Thailand behind to embark on a 2000km journey to the Indonesian island of Sumatra.

The teams must travel through the populous Indonesian island of Sumatra, where they will endure an ad-hoc transport system, limited accommodation options and virtually zero English spoken.

Five intrepid duos are tasked with undertaking the trip of a lifetime, racing over 14,000km across the world’s largest continent, Asia, taking in three of its nations – China, Nepal and India.

Five teams set off from Vancouver on a race across Canada. Without smartphones, internet access or credit cards, they will need plenty of ingenuity to make it to the finish line in Newfoundland.