Punjab, a state bordering Pakistan, is the heart of India’s Sikh community. The city of Amritsar, founded in the 1570s by Sikh Guru Ram Das, is the site of Harmandir Sahib, the holiest gurdwara (Sikh place of worship). Known in English as the Golden Temple, and surrounded by the Pool of Nectar, it's a major pilgrimage site. Also in Amritsar is Durgiana Temple, a Hindu shrine famed for its engraved silver doors. Punjab is a geographical and cultural region in the northern part of South Asia, comprising areas of eastern Pakistan and northern India. Not being a political unit, the extent of the region is the subject of debate and focuses on historical events to determine its boundaries. The Punjab region has been inhabited by Indus Valley Civilisation, Indo-Aryan peoples, Indo-Scythians and has seen numerous invasions by the Achaemenid Empire, Greeks, Kushan Empire, Ghaznavids, Timurids, Mughals, Afghans, British and others. The foreign invaders mainly targeted the most productive region of Punjab known as the Majha region, located in central part of Punjab, which is also the bedrock of Panjabi culture and traditions. The people of the Punjab today are called Punjabis and their principal language is called Punjabi. The main religions of the Punjab region are Islam, Sikhism and Hinduism. Other religious groups are Christianity, Jainism and Buddhism.