The Thar Desert and Aravalli hills are situated in between the Indus and Gangetic plains. Mount Abu is the highest point (5650 ft.) in the Aravalli hills. The Ganges river rises in the Himalayas, flows south and then towards the east. The river Yamuna flows almost parallel to the Ganges and then joins it. The area between these two rivers is called doab – meaning the land between two rivers. The important tributaries of the Ganges are the Gomati, Sarayu, Ghagra and Gandak.

In the east of India, the Ganges plain merges into the plains of Brahmaputra. The river Brahmaputra rises beyond the Himalayas, flows across Tibet and then continues through the plains of northeast India. In the plains, it is a vast but a slow-moving river forming several islands.

The Indo-Gangetic plain has contributed to the rise of urban centres, particularly on the river banks or at the confluence of rivers. The Harappan culture flourished in the Indus valley. The Vedic culture prospered in the western Gangetic plain. Banares, Allahabad, Agra, Delhi and Pataliputra are some of the important cities of the Gangetic plain. The city of Pataliputra was situated at the confluence of Son river with the Ganges. In the ancient period Pataliputra had remained the capital for the Mauryas, Sungas, Guptas and other kingdoms.

The most important city on the western side of the Gangetic plain is Delhi. Most of the decisive battles of Indian history such as the Kurukshetra, Tarain and Panipat were fought near Delhi. Also, this plain had always been a source of temptation and attraction for the foreign invaders due to its fertility and productive wealth. Important powers fought for the possession of these plains and valleys. Especially the Ganga-Yamuna doab proved to be the most coveted and contested area.

The rivers in this region served as arteries of commerce and communication. In ancient times it was difficult to make roads, and so men and material were moved by boat. The importance of rivers for communication continued till the days of the East India Company.

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