Clive Anderson takes to the railways where he meets a nomadic tribe, visits Buddhist caves, experiences the Mongolian Stock Exchange, and ends up on the Trans-Siberian Express.

Former Kirov prima ballerina Natalia Makarova explores the railways of Russia, taking in Volgograd, Samarkand and the river Volga, and dancing on the railway itself.

Michael Palin travels through Northern Ireland and Ireland and finds out more about his Irish ancestors, experiences the "peace train" from Belfast to Dublin, and visits Cork.

Poet and author Lisa St Aubin de Terán travels from Brazil to Bolivia, taking in scenes of both lush beauty and abject poverty, and crossing a swamp larger than Britain.

BBC correspondent Mark Tully travels on the first train for a decade to go through the Khyber Pass, closed since the end of the Soviet-Afghan war.

Author and anti-apartheid campaigner Rian Milan travels across South Africa and wrestles with its troubled past, taking in Durban, Johannesburg and the Lost City.