From Russia to Iran: Crossing the Wild Frontier

Levison experiences breathtaking landscapes, bizarre ruins and a Sufi ceremony and crosses Chechnya - now ruled by a terrifying strongman - into Dagestan, where terrorists hide out in the mountains.

In Dagestan - which the Foreign Office warns against visiting - Levison experiences warrior clans' hospitality, stunning beauty and ancient cities. Then it's on to country-of-contrasts Azerbaijan.

In Azerbaijan - a rugged country known as The Land of Fire - Levison travels through an area known for breeding IS fighters and passes Stalin's birthplace.

The fourth episode of Levison Wood's epic 2600-mile journey sees the explorer travel the final 1000 miles by any means possible through Armenia and the captivating Republic of Iran, aiming for the Caspian Sea and his journey's end. Entering Armenia, Lev teams up with a seasoned photojournalist Anush Babajanyan who helps get him access to Europe's forgotten war zone, in the contested state of Nagorno-Karabakh. This contested region is claimed by Armenia and Azerbaijan. Over the last 30 years, up to 30,000 people have been killed in a war the rest of Europe has forgotten. They meet war veteran, Eduard, and his family who live perilously close to the frontline, under daily threat of Azeri rockets, before venturing to the frontline trenches where soldiers engage in daily conflict. Heading south, Lev enters Iran, a country that has had a rocky relationship with the West since the 1979 Islamic revolution drove out the American-backed monarchy.

Levison travels through Armenia and Europe's forgotten warzone Nagorno-Karabakh, before heading into Iran towards Tehran, the Caspian Sea and the journey's end.