Rawalpindi (Punjabi, Urdu: راولپنڈى‎, Rāwalpiṅḋī), commonly known as Pindi (Punjabi: پنڈی), is a rapidly growing city in the Pothohar region of northern Punjab, Pakistan. It is located only 14 kilometres (9 mi) south from the capital city of Islamabad, in the province of Punjab. The Rawalpindi/Islamabad metropolitan area is ranked the third highest in the country. Due to the high interdependence and intertwined areas of the two cities, they are known as the twin cities of Rawalpindi/Islamabad. In the 1950s, Rawalpindi was smaller than Hyderabad and Multan, but the city's economy received a boost during the building of Islamabad (1959–1969), during which Rawalpindi served as the national capital. Rawalpindi is in the northernmost part of the Punjab province, located 275 km (171 mi) to the north-west of Lahore. It is the administrative seat of the Rawalpindi District. Also, Rawalpindi is the military headquarters GHQ of the Pakistani Armed Forces.