Kolkata /koʊlˈkɑːtɑː/, also known historically in English as Calcutta /kælˈkʌtə/, is the capital of the Indian state of West Bengal. Located on the east bank of the Hooghly river, it is the principal commercial, cultural, and educational centre of East India, while the Port of Kolkata is India's oldest operating port as well as its sole major riverine port.
As of 2011, the city had 4.5 million residents; the urban agglomeration, which comprises the city and its suburbs, was home to approximately 14.1 million, making it the third-most populous metropolitan area in India. As of 2008, its economic output as measured by gross domestic product ranked third among South Asian cities, behind Mumbai and Delhi. As a growing metropolitan city in a developing country, Kolkata confronts substantial urban pollution, traffic congestion, poverty, overpopulation, and other logistic and socioeconomic problems.
The word Kolkata derives from the Bengali term Kôlikata (Bengali: কলিকাতা) [ˈkɔlikat̪a], the name of one of three villages that predated the arrival of the British, in the area where the city eventually was to be established; the other two villages were Sutanuti and Govindapur.
The discovery and archaeological study of Chandraketugarh, 35 kilometres (22 mi) north of Kolkata, provide evidence that the region in which the city stands has been inhabited for over two millennia Kolkata's recorded history began in 1690 with the arrival of the English East India Company, which was consolidating its trade business in Bengal. Job Charnock, an administrator who worked for the Company, is traditionally credited as the founder of the city; in response to a public petition, the Calcutta High Court ruled in 2003 that the city does not have a founder.
The area occupied by the present-day city encompassed three villages: Kalikata, Gobindapur, and Sutanuti. Kalikata was a fishing village; Sutanuti was a riverside weavers' village. They were part of an estate belonging to the Mughal emperor; the jagirdari (a land grant bestowed by a king on his noblemen) taxation rights to the villages were held by the Sabarna Roy Choudhury family of landowners, or zamindars. These rights were transferred to the East India Company in 1698.
Spread roughly north–south along the east bank of the Hooghly River, Kolkata sits within the lower Ganges Delta of eastern India; the city's elevation is 1.5–9 m (5–30 ft). Much of the city was originally a wetland that was reclaimed over the decades to accommodate a burgeoning population. The remaining undeveloped areas, known as the East Kolkata Wetlands, were designated a "wetland of international importance" by the Ramsar Convention (1975). As with most of the Indo-Gangetic Plain, the soil and water are predominantly alluvial in origin.
Kolkata is located over the "Bengal basin", a pericratonic tertiary basin. Bengal basin comprises three structural unit: shelf or platform in the west; central hinge or shelf/slope break; and deep basinal part in the east and southeast. Kolkata is located atop the western part of the hinge zone which is about 25 km (16 mi) wide at a depth of about 45,000 m (148,000 ft) below the surface. The shelf and hinge zones have many faults, among them some are active.
Total thickness of sediment below Kolkata is nearly 7,500 m (24,600 ft) above the crystalline basement; of these the top 350–450 m (1,150–1,480 ft) is quaternary, followed by 4,500–5,500 m (14,760–18,040 ft) of tertiary sediments, 500–700 m (1,640–2,300 ft) trap wash of cretaceous trap and 600–800 m (1,970–2,620 ft) permian-carboniferous Gondwana rocks. The quaternary sediments consist of clay, silt, and several grades of sand and gravel.
These sediments are sandwiched between two clay beds: the lower one at a depth of 250–650 m (820–2,130 ft); the upper one 10–40 m (30–130 ft) in thickness. According to the Bureau of Indian Standards, on a scale ranging from I to V in order of increasing susceptibility to earthquakes, the city lies inside seismic zone III; according to a United Nations Development Programme report, its wind and cyclone zone is "very high damage risk".
Kolkata is known for its literary, artistic, and revolutionary heritage; as the former capital of India, it was the birthplace of modern Indian literary and artistic thought. Kolkata has been called the "City of Furious, Creative Energy" as well as the "cultural [or literary] capital of India". The presence of paras, which are neighbourhoods that possess a strong sense of community, is characteristic of the city.
Typically, each para has its own community club and, on occasion, a playing field. Residents engage in addas, or leisurely chats, that often take the form of freestyle intellectual conversation. The city has a tradition of political graffiti depicting everything from outrageous slander to witty banter and limericks, caricatures, and propaganda.