Explanation:

Digboi is a town and a town area committee in Tinsukia district in the north-eastern part of the state of Assam, India Crude oil was discovered here in late 19th century and first oil well was dug in 1866. Digboi is known as the Oil City of Assam where the first oil well in Asia was drilled. The first refinery was started here as early as 1901. Digboi has the oldest oil well in operation. With a significant number of British professionals working for Assam Oil Company until the decade following independence of India, Digboi had a well-developed infrastructure and a number of bungalows unique to the town. It has eighteen holes golf course as part of the Digboi Club. It has guest houses and tourist residential apartments laid on Italian architectural plan to promote tourism in upper Assam.