Home to the two most populous countries on earth - China and India - Asia is a huge continent with dramatically contrasting landscapes and cultures. To travel in Asia is to experience a society where the modern world exists alongside a far older one. From Manchuria in China's frigid north to the sultry palm-lined Kerala Backwaters in the deep south of India, from the icy peaks of the Himalayas in Nepal to the lush tea-plantations of Sri Lanka, whichever tour you choose you'll discover the huge range of contrasts that Asia has to offer.