Shimla lies in the south-western ranges of the Himalayas at 31.61N 77.10E. It has an average altitude of 2, 206 metres (7, 238 ft) above mean sea level and extends along a ridge with seven spurs. The city stretches nearly 9.2 kilometres (5.7 mi) from east to west.[17] Shimla was built on top of a total of seven different hills namely: Inverarm Hill, Observatory Hill, Prospect Hill, Summer Hill, Bantony Hill, Elysium Hill and Jakhoo Hill. The highest point in Shimla is the Jakhoo hill, which is at a height of 2, 454 metres (8, 051 ft). The city is a Zone IV (High Damage Risk Zone) per the Earthquake hazard zoning of India. Weak construction techniques and an increasing population pose a serious threat to the already earthquake prone region.There are no water bodies near the main city and the closest river, the Sutlej, is about 21 km (13 mi) away.Other rivers that flow through the Shimla district, although further from the city, are the Giri, and Pabbar (both tributaries of Yamuna). The green belt in the Shimla planning area is spread over 414 hectares (1, 020 acres).The main forests in and around the city are of pine, deodar, oak and rhododendron.Environmental degradation due to the increasing number of tourists every year without the infrastructure to support them has resulted in Shimla losing its popular appeal as an ecotourism spot.Another rising concern in the region are the frequent number of landslides that often take place after heavy rains. The city is situated 88 km (55 miles) northeast of Kalka, 116 km (72 miles) northeast of Chandigarh, 247 km (154 miles) south of Manali and 350 km (219 miles) northeast of Delhi, the national capital. Kalka can be reached within 2.5 hours, Chandigarh can be reached in 3 hours and 15 minutes. Delhi and Manali are both around 7 hours away from Shimla.