Kalyan Airstrip is an abandoned World War II airstrip at Nevali 6 km south of Kalyan railway station and 55 km north of Mumbai airport, India. The airfield served RAF Kalyan and was abandoned after the war. It is owned by the Ministry of Defence but has been encroached upon. In 2006, the site was proposed as a candidate for the second airport for the Mumbai Metropolitan Region. However, this proposal was abandoned in February 2014 as the Maharashtra government dropped the idea of examining alternative sites, having secured all necessary approvals for the Navi Mumbai International Airport at Panvel. History The airfield at Nevali was used by the RAF pilots during World War II to give operational cover to the Bombay region. The total area of the Nevali air base was over . Post-Independence, ownership of the land was transferred to the Ministry of Defence. In June 2017, the Navy began constructing a boundary wall to protect the remaining land from further encroachment, since around 400 acres of the land was encroached upon over the years. A small portion of the land is used by the Bhabha Atomic Research Centre (BARC) for research activities. Proposal to use site for International Airport In October 2006 the Government of Maharashtra first proposed the Kalyan-Nevali site as a candidate for a second airport for the Mumbai Metropolitan Region. However, the Ministry of Civil Aviation was not very keen on the idea and wanted to focus on the second airport in Navi Mumbai. The Kalyan site was proposed because, compared to the Panvel site, the total area of the Nevali Airbase was over relatively free of any natural obstacles and, unlike the Panvel site, there was no possibility of CRZ (Coastal Regulatory Zone) violations, flattening of mountains or diversion of any rivers. The Union Ministry of Environment and Forests had raised environmental objections on the proposed location of the Navi Mumbai International Airport near Kopra Panvel area, because the construction of the airport would involve reclamation of low-lying areas in an ecologically fragile zone as well as destruction of several hectares of mangroves. Hence the State Government proposed several alternate sites, one of which centred on a piece of land owned by the Airports Authority of India near Kalyan In August 2007, the national security advisor (NSA) had communicated to the state chief minister that the airport could not be developed on the