Delhi lies in Northern India. It borders the Indian states of Haryana on the north, west and south and Uttar Pradesh (UP) to the east. During theBritish Raj, Delhi was part of the province of Punjab and is still historically and culturally connected to the Punjab region. Two prominent features of the geography of Delhi are the Yamuna flood plains and the Delhi ridge. The Yamuna river was the historical boundary between Punjab and UP, and its flood plains provide fertile alluvial soil suitable for agriculture but are prone to recurrent floods. The Yamuna, a sacred river in Hinduism, is the only major river flowing through Delhi. The Hindon River separates Ghaziabad from the eastern part of Delhi. The Delhi ridge originates from the Aravalli Range in the south and encircles the west, north-east and north-west parts of the city. It reaches a height of 318 m (1,043 ft) and is a dominant feature of the region