The Cellular Jail, also known as Kālā Pānī (lit. 'Black Water'), was a British colonial prison in the Andaman and Nicobar Islands. The prison was used by the colonial government of India for the purpose of exiling criminals and political prisoners. Many notable independence activists, including Diwan Singh Kalepani, Yogendra Shukla, Batukeshwar Dutt, Shadan Chandra Chatterjee, Sohan Singh, Vinayak Savarkar, Hare Krishna Konar, Shiv Verma, Allama Fazl-e-Haq Khairabadi, and Sudhanshu Dasgupta were imprisoned here during the struggle for India's independence.[2] Today, the complex serves as a national memorial monument.this format was based on Jeremy Bentham's idea of the Panopticon. The wings radiated from the tower in straight lines, much like the spokes of a bicycle wheel.