Secunderabad, also spelled as Sikandarabad, is a twin city of Hyderabad and one of the six zones of the Greater Hyderabad Municipal Corporation (GHMC) in the Indian state of Telangana. It is the headquarters of the South Central Railway zone. Named after the Mir Akbar Ali Khan Sikander Jah, Asaf Jah III, Nizam of the Asaf Jahi dynasty, Secunderabad was established in 1806 as a British cantonment. Although both the cities are together referred to as the twin cities, Hyderabad and Secunderabad have different histories and cultures, with Secunderabad having developed directly under British rule until 1948, and Hyderabad as the capital of the Nizams' princely state of Hyderabad. Since 1956, the city has housed the Rashtrapati Nilayam, the winter office of the president of India.

Hyderabad is the capital and largest city of the Indian state of Telangana. It occupies 650 km2 (250 sq mi) on the Deccan Plateau along the banks of the Musi River, in the northern part of Southern India. With an average altitude of 542 m (1,778 ft), much of Hyderabad is situated on hilly terrain around artificial lakes, including the Hussain Sagar lake, predating the city's founding, in the north of the city centre. According to the 2011 census of India, Hyderabad is the fourth-most populous city in India with a population of 6.9 million residents within the city limits, and has a population of 9.7 million residents in the metropolitan region, making it the sixth-most populous metropolitan area in India. With an output of US$74 billion, Hyderabad has the fifth-largest urban economy in India.