Explanation:

India is located in the South Asian region and has a vast coastline that stretches to 7,517 km. The location of India is a major factor that helped it to establish close contacts with various countries. However, the Deccan Peninsula played a significant role in establishing these contacts.

Central Location:
India's central location made it a hub for trade and commerce. It was strategically located on the trade routes between the East and the West. India was a crucial link in the chain of the ancient maritime trade network that connected the Mediterranean world with East Africa and South Asia. The Arab traders used to come to India for spices, textiles, and other commodities, which they then sold in the Mediterranean world.

Indian Landmass:
The Indian landmass was also a significant factor that helped India establish close contacts with various countries. The landmass provided a natural barrier that protected India from foreign invasions. The Himalayas in the north and the Indian Ocean in the south provided natural barriers that protected India from invaders. The landmass also provided a vast area for agriculture, which was the primary means of livelihood for the people.

Deccan Peninsula:
The Deccan Peninsula is a vast plateau that separates the Arabian Sea and the Bay of Bengal. The peninsula was strategically located, and it was a significant factor that helped India establish close contacts with West Asia, Africa, Europe, Southeast Asia, and East Asia. The Deccan Peninsula was a hub for trade and commerce. The ports on the west coast of India were used by the Arab traders to trade with the West, while the ports on the east coast were used by the Southeast Asian traders to trade with India.

Moreover, the Deccan plateau also provided a vast area for agriculture, which was the primary means of livelihood for the people. The plateau was rich in minerals and provided a source of income for the people. The Deccan plateau was also a center of culture and art. The various dynasties that ruled the region contributed to the development of art and architecture.

In conclusion, the Deccan Peninsula played a significant role in establishing close contacts between India and various countries. The peninsula was strategically located, and it was a hub for trade and commerce. The ports on the west coast of India were used by the Arab traders to trade with the West, while the ports on the east coast were used by the Southeast Asian traders to trade with India. The Deccan plateau also provided a vast area for agriculture, which was the primary means of livelihood for the people.

The Trans Indian routes helped India to establish close contact with east and west Asia.