Amritsar is the largest and most important city in the noothern state Punjab in northwestern India and is a major commercial, cultural, and transportation centre. Amritsar derives its name from Am?it-sarovar literally meaning "Pool of Nectar".It lies about 15 miles (25 km) east of the border with Pakistan. It is also the centre of Sikhism and the site of the Sikhs' principal place of worship, the Harimandir, or Golden Temple. Amritsar is one of the most ancient and fascinating cities of India. It is an important seat of Sikh history and culture. Being the gateway for travellers coming to India on the overland route from central Asia it soon became the centre of various commercial activities. The city is dominated by the history of the Sikhs and many of their sacred shrines are found in and around the city. It was established by Guru Ramdas. The city has highest temporal seat of Sikhs "The Harimandir Sahib" popularly known as Golden Temple. The city has central old city called walled city. It has narrow zig zag streets mostly developed in the 17th and 18th century. The city has a peculiar example of introvert planning system and has uniques areas called Katras. The Katras are self styled residential units that provided unique defence system during attacks on the city.