3. Pin Parvati trek
The Pin Parvati Pass trek is one of the most difficult treks in India, and is meant only for those with experience. Located at a height of 17,450 feet, the Pin Parvati Pass is the only link between the green Parvati Valley of Kullu and the dry, arid Pin Valley in Spiti. On this trekking route in Himachal, you will start from Manali, and trek through the green valleys of Himachal Pradesh, through fruit orchards, blossoming wildflowers, and sparkling rivers and streams. Once you reach Pin Parvati Pass, you'll see the brown and grey rocky landscape of the Spiti valley. For almost 10 days, you’ll be far away from civilization, crossing wide glaciers, climbing steep slopes, and trekking through thick forests. This makes the Pin Parvati Pass trek one of the most difficult treks in India.