For centuries, Tibet was one of the most isolated parts of the world, a high plateau averaging 4,000 m above sea level, bound by the Himalayas, the Karakoram and the Kunlun ranges. Crossing the high passes to the plateau was a high-risk affair until the first roads were built, but until the advent of scheduled commercial flights from Chengdu in the 1970s, it took a bone-jarring 40-hour ride in decrepit buses to get from Qinghai province – formerly the Tibetan province of Amdo – to Lhasa. All that changed with the Qinghai-Tibet or Qingzang railway.

Hanoi is a beautiful city which retains an air of French colonial elegance with pretty yellow stucco buildings lining leafy streets - a big contrast to bustling Ho Chi Minh in the south.

Hidden in the Himalayas, Bhutan is like no other countries. Most men still wear the traditional gho to work, most houses are in traditional architecture and Gross National Product gives way to Gross National Happiness.

Mongolia lies at the heart of Asia, between China and the vast wilderness of Siberia. In the far west of this huge, sparsely populated country live the minority Kazakh nomads in the Altai Mountains. Their heritage of hunting with magnificent Golden Eagles has been revived, and each year just before the onset of the winter hunting season, they meet for the annual Golden Eagle festival, testing both the birds and their handlers, as well as providing a platform for a gathering of the nomads to meet and play their traditional sports.

This is an expedition down the Mekong, one of Asia’s great rivers, starting in Southern China, past Myanmar to Thailand, and then on to Laos.

The second part of our World Religions series visits the origins of three great monotheistic religions - Judaism, Christianity and Islam. Apart from the fascinating sites holy to more than half the world, experience the wonder of Petra, one of the world's great man-made sights.