Goa is a state on the southwestern coast of India within the region known as the Konkan, and geographically separated from the Deccan highlands by the Western Ghats. It is surrounded by the Indian states of Maharashtra to the north and Karnataka to the east and south, with the Arabian Sea forming its western coast. It is India's smallest state by area and the fourth-smallest by population. Goa has the highest GDP per capita among all Indian states, two and a half times that of the country. Panaji is the state's capital, while Vasco da Gama is its largest city. The historic city of Margao still exhibits the cultural influence of the Portuguese, who first landed in the early 16th century as merchants and conquered it soon thereafter. Goa was a former state of the Portuguese Empire. The Portuguese overseas territory of Portuguese India existed for about 450 years until it was annexed by India in 1961. Goa is visited by large numbers of international and domestic tourists each year for its white sand beaches, nightlife, places of worship and World Heritage-listed architecture. It has rich flora and fauna, owing to its location on the Western Ghats range, a biodiversity hotspot.