The capital of the Surasena Mahajanapada was:

The capital of the Surasena (Shurasena) Mahajanapada was Mathura, on the banks of the Yamuna river, in present-day Uttar Pradesh.

About Surasena:

• It was one of the 16 Mahajanapadas of the 6th century BCE.
• It was located in the region around Mathura and Vrindavan, called the "Braj" region.
• It was ruled by the Yadavas, according to tradition.
• Its king Avantiputra was a follower of the Buddha, according to Buddhist texts.
• The Greek writer Megasthenes mentioned the "Sourasenoi" people and their cities, Methora (Mathura) and Kleisobora, and said that they worshipped "Herakles" (whom many scholars identify with Krishna).

About Mathura:

• It is famous as the birthplace of Lord Krishna, and is one of the seven sacred cities (Saptapuri) of Hinduism.
• It was an important trade centre, on the routes connecting north-western India with the Ganga plains and western India.
• It was a great centre of art, and gave its name to the "Mathura school" of sculpture, which used red sandstone and produced Buddhist, Jain and Hindu images.
• It was an important centre of Buddhism and Jainism; the Kankali Tila Jain stupa was found there.
• Many inscriptions and sculptures of the Shunga, Shaka and later periods have been found there.
• The Government Museum, Mathura, has a famous collection of ancient sculptures.

Mathura in religion:

• Hindus celebrate Krishna Janmashtami here with great enthusiasm.
• Vrindavan, Gokul, Govardhan and Barsana in the Braj region are associated with Krishna's childhood.

Why not the other options?

• ✗Kampilya was the capital of South Panchala.
• ✗Indraprastha was the capital of the Kurus in the epic.
• ✗Viratanagara was the capital of another Mahajanapada.