Himachal is an obvious choice of destination for summer for people from the plains in Delhi, Punjab and Chandigarh. While Shimla may be the de-facto destination, more exotic places in the north are meant for those with an adventurouse spirit. That doesn't mean you have to be strong and fit to access these higher regions of the Himalayas, as most places are close to road networks.
Overview. Most of the places in Lahaul and Spiti are at heights more than 10,000 feet, with highest point close to 15,000 feet. Yet, it is not forbiddingly cold in the summers and is not very demanding on the traveller's physique. But a possibility of altitude sickness always exists. Sun tends to be harsh in these climates and it is necessary to carry sunscreen.
Best way to do this section of Himachal is by hiring a jeep. Public transport does exist but not frequent, so you will have to do some planning and know bus timings in advance. The adventurous lot can do it in bikes. The road is scenic in many parts and you might want to take it slow and easy, enjoying the views, which means you will be better off with your own transport instead of relyaing on buses.
Some passes on the road are closed in winter and open in May-June. So if you are planning the trip early in summer, check first if Rohtang Pass and Kunzum La have been thrown open to traffic.
Orientation. While Manali and Shimla are connected by a highway via Mandi and Kullu towns, there is another longer detour you can take, passing through Lahaul and Spiti. For this, start from Shimla and head to Kinnaur on Hindustan-Tibet road. The road goes along Sutlej river in Kinnaur, and as you enter Spiti Valley from Kinnaur, traverses along Spiti River. Further, beyond Kunzum La where Spiti Valley ends, the road goes along Chandra river in the valley of Lahaul till you climb up to Rohtang Pass and eventually reach Manali. The major towns along the way are Rekong Peo(which is a short detour from Hindustan-Tibet road) and Kaza. The road takes you through some great mountain scenery and a few Buddhist monasteries.
Places to Visit
Listed her are places worth a visit, ordered as they appear when you go from Shimla to Manali.
Sangla and Chitkul. Sangla is a detour from Hindustan-Tibet road. Sangla Valley is known for its views of snow-capped mountains and scenic locales. Chitkul, which is further from Sangla on the same road is the last village you encounter near Tibet border.
Kalap Village. Located just above Rekong Peo town, Kalpa is a good summer retreat for people of Delhi and Punjab. The village is also known for its views of Kinner Kailash range of mountains.
Nako Lake. Nako Village is an ideal place to spend a night on the way from Kalpa to Kaza. Nako has a small high altitude lake, which is one its attractions.
Dhangkar Monastery. The ancient Dhankar monastery is said to be 400 years old. At more than 12,000 feet high, Dhankar is one of the most scenic locales in Spiti Valley. Another attraction here is a beautiful high altitude lake.
Tabo and Ki Monastery. The monastery in Tabo, the oldest in the region is more than 1000 years old. This, along with Alchi monastery in Ladakh is declared a word heritage site. Tabo's ancient monastery is known for rich frescoes in its nine temples. Ki Monastery is located close to Kaza town in a picturesque location in Spiti, and is said to be 800 years old.
Kibber Village. Located above 14,000 feet, Kibber was once known as the highest village in the world with permanent habitation. The status is now lost, with better access to remote places in the Himalayas over the years. Kibber offers good high altitude walks, and has picturesque views of Spiti Valley from its heights.
Kunzum La. Kunzum La is the highest point in the journey, at almost 15,000feet. The pass marks the boundary between Spiti Valley and Lahaul. There is a small temple to Kunzum Devi at the pass. The pass also serves as the starting point for the trek to Chandratal Lake.
Chandratal. This is a beautiful high altitude lake located besides Chandra river, and is a 15km detour from the main road. The road to Chandratal is the last to open after winter, so always check before you leave. But there is always the option to walk here from Kunzum La.
Rohtang Pass. Rohtang Pass separates the valley of Chandra river in Lahaul with the valley of Beas that leads to Manali. While Lahaul is like a high altitude desert in rain shadow, greenery starts making its mark after Rohtang. Rohtang is a popular tourist destination due to availability of snow till late in the summer, and its easy access.
Food and Accommodation.
There is basic accommodation available all through the way. The villages where you can find guesthouses include Sangla, Kalpa, Nako, Kaza, Kibber and Batal. You can also find accommodation in Ki and Tabo monasteries. There is no comfortable mid-range or high end accommodation available anywhere on the road.