The National Capital Region (NCR) is a name for the coordinated planning region which encompasses the entire National Capital Territory of Delhi as well as several surrounding districts in the neighbouring states of Uttar Pradesh, Haryana and Rajasthan. However, since not all of the aforementioned areas are completely urban, the Delhi conurbation is actually limited to the NCT of Delhi and the neighbouring contiguous urban areas comprising Gurgaon, Faridabad, Noida, (Greater Noida) and Ghaziabad lying in ""Central National Capital Region (CNCR)"", a small part of overall NCR. The population of this conurbation was estimated 21.7 million in 2011. It is the world's third most populous urban agglomeration.