The southern half of India is a largely upland area that thrusts a triangular peninsula (c.1,300 mi/2,090 km wide at the north) into the Indian Ocean between the Bay of Bengal on the east and the Arabian Sea on the west and has a coastline c.3,500 mi (5,630 km) long; at its southern tip is Kanniyakumri (Cape Comorin). In the north, towering above peninsular India, is the Himalayan mountain wall, where rise the three great rivers of the Indian subcontinent—the Indus, the Ganges, and the Brahmaputra.
The Gangetic alluvial plain, which has much of India's arable land, lies between the Himalayas and the dissected plateau occupying most of peninsular India. The Aravalli range, a ragged hill belt, extends from the borders of Gujarat in the southwest to the fringes of Delhi in the northeast. The plain is limited in the west by the Thar (Great Indian) Desert of Rajasthan, which merges with the swampy Rann of Kachchh to the south. The southern boundary of the plain lies close to the Yamuna and Ganges rivers, where the broken hills of the Chambal, Betwa, and Son rivers rise to the low plateaus of Malwa in the west and Chota Nagpur in the east.
The Narmada River, south of the Vindhya hills, marks the beginning of the Deccan. The triangular plateau, scarped by the mountains of the Eastern Ghats and Western Ghats, is drained by the Godavari, Krishna, and Kaveri rivers; they break through the Eastern Ghats and, flowing east into the Bay of Bengal, form broad deltas on the wide Coromandel Coast. Further north, the Mahanadi River drains India into the Bay of Bengal. The much narrower western coast of peninsular India, comprising chiefly the Malabar Coast and the fertile Gujarat plain, bends around the Gulf of Khambat in the north to the Kathiawar and Kachchh peninsulas. The coastal plains of peninsular India have a tropical, humid climate.
The Deccan interior is partly semiarid on the west and wet on the east. The Indo-Gangetic plain is subtropical, with the western interior areas experiencing frost in winter and very hot summers. India's rainfall, which depends upon the monsoon, is variable; it is heavy in Assam and West Bengal and along the southern coasts, moderate in the inland peninsular regions, and scanty in the arid northwest, especially in Rajasthan and Punjab.
The republic is divided into 28 states: Andhra Pradesh; Arunachal Pradesh; Assam; Bihar; Chhattisgarh; Goa; Gujarat; Haryana; Himachal Pradesh; Jammu and Kashmir (see Kashmir); Jharkhand; Karnataka; Kerala; Madhya Pradesh; Maharashtra; Manipur; Meghalaya; Mizoram; Nagaland; Odisha (Orissa); Punjab; Rajasthan; Sikkim; Tamil Nadu; Tripura; Uttarakhand; Uttar Pradesh; and West Bengal (see Bengal). There are also seven union territories: the Andaman and Nicobar Islands; Chandigarh; Dadra and Nagar Haveli; Daman and Diu; Delhi; Lakshadweep; and Puducherry. Kashmir is disputed with Pakistan.
In 1991, India had 23 cities with urban areas of more than 1 million people: Ahmadabad, Bangalore (Bengaluru), Bhopal, Chennai (Madras), Coimbatore, Delhi, Hyderabad, Indore, Jaipur, Kanpur, Kochi (see under Cochin), Kolkata (Calcutta), Lucknow, Ludhiana, Madurai, Mumbai, Nagpur, Patna, Pune, Surat, Vadodara (see under Baroda), Varanasi, and Vishakhapatnam.