Chris travels through Turkey, reflecting on the achievements of Mustafa Kemal Ataturk - the founder of the republic who oversaw the modernisation of the country and its railways. He begins his journey at Istanbul railway station, the starting point ort he Marmaray rail tunnel, which passes beneath the Bosphorus and was built to withstand earthquakes. He also visits Ankara and the volcanic spires of Cappadocia, before heading deep into the mountains and ending in the remote borderlands city of Kars.

• Chris Tarrant