Towards the western end of the Himalayas a series of continuous mountain ridges, comprising scores of 6000 metre (20000 foot) peaks, forms an effective barrier between the Indian provinces of Lahaul and Ladakh. Linking these contrasting mountainous regions is a trekking route that provides one of the great challenges of the Indian Himalaya. Transferring by train and car from Delhi, we pass through the lush Kulu Valley and cross the Rohtang Pass to reach the start of our trek at Darcha. From here, we head north across the Shingo La (c.5100m./16000ft.) into the ancient kingdom of Zanskar, famous for its hardy inhabitants and starkly beautiful landscape. En route, we encounter a succession of isolated villages and several wonderful Buddhist monasteries, notably at Phuktal, Lingshet and Lamayuru. As a finale to what is unquestionably one of the world's classic trekking experiences, there is also time to explore the fascinating Ladakhi capital of Leh.