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.

The race to Ushuaia is underway, and the five teams head out of Copan Ruinas in western Honduras to their next checkpoint – Panama City

Setting off from Panama City, they take to the Caribbean Sea, bypassing the most dangerous place in the Western Hemisphere - the Darien Gap.

As the 25,000km race to Ushuaia approaches the half-way mark, the four teams compete not just with each other but with the extreme altitudes of Peru.

To reach the next checkpoint - Cafayate in Argentina - teams must choose to travel through either Bolivia or Chile, but an unstable political climate in both countries puts everyone’s journeys at risk.

With three teams at the checkpoint at Cafayate in Argentina, one team is yet to arrive. Dom and Lizzie are over 24 hours behind their competitors and after a disastrous last leg must rely on all their ingenuity to claw their way back into the race.

With two teams at the checkpoint – Ilha Grande in Brazil – the remaining teams are engaged in a frantic race to avoid finishing the leg in last place.

The teams embark on the final leg of their journey, heading off on the 4,800 kilometre trek to the finish line in Ushuaia, Argentina, the most southerly city in the world. However, as they prepare to leave the last checkpoint, one of the teams reveals that they have run out of money and will not be completing the challenge. The three remaining pairs rely on different tactics to get ahead, benefiting from risky gambles, lucky opportunities and the kindness of strangers.

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.

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 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.

In the first episode, the teams set off from Mexico City – a gargantuan metropolis and the largest Spanish speaking city in the world.

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.

Twelve minutes is all that separates the first two teams as they embark on the final leg of their Race Across the World from Jakarta to Lombok.

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 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 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.