Concept:Pakyong Airport is a Greenfield airport located in the state of Sikkim.Explanation:It is situated near Gangtok, the capital of Sikkim.This airport is the 100th operational airport in India built under the UDAN scheme (Ude Desh Ka Aam Nagrik).Greenfield airports are constructed on waste green lands, considering environmental costs and damages.Thus, Pakyong Airport is located in Sikkim.Answer:Sikkim