Baku (; , from the medieval "Bâd-kube", meaning "wind-pounded city", a compound word of "bād", "wind", and "kube", which is rooted in the verb کوبیدن "kubidan", "to pound", thus meaning a place where the wind would be strong and pounding, and ancient city names "Baraca"/, "Pakovan"/) is the capital) is the capital and the largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. It is on the southern shore of the Apsheron Peninsula. Baku is located below sea level, which makes it the lowest lying national capital in the world and also the largest city in the world located below sea level. Modern Baku has three parts: the Old Town (İçəri Şəhər), the boomtown and the Soviet-built town. About 3 million people live in the metropolitan area. There are large numbers of refugees and internally displaced persons.