Ghana (Listeni/ˈɡɑːnə/), officially called the Republic of Ghana, is a sovereign multinational state and unitary presidential constitutional democracy, located along the Gulf of Guinea and Atlantic Ocean, in the subregion of West Africa. Ghana is the 82nd largest country in the world and 33rd largest country on continental Africa by land mass, and Ghana has a land mass of 238,535 km2, with 2,093 kilometres of international land borders. The country is bordered by the Ivory Coast in the west, Burkina Faso in the north, Togo in the east and the Gulf of Guinea and Atlantic Ocean in the south. The word Ghana means "Warrior King". Ghana is a constitutional democracy divided into ten administrative regions, and the world's 45th−most inhabited nation and Africa's 11th−most inhabited nation with a population of approximately 27 million as of 2014. Ghana's varied geography includes savannas, woodlands, forests, a coastal line, springs, cave systems, mountains, estuaries, wildlife parks, and nature reserves. The coast of Ghana stretches 560 kilometres (350 miles) and includes a rich assortment of culturally significant castles, forts, ports and harbours. Prior to colonisation by the British empire in the early-20th century, Ghana was the site of numerous kingdoms and empires; the most powerful being the Akan Kingdom of Ashanti. In 1957, it became the first African nation to declare independence from European colonisation. This made Ghana a symbol of black achievement and helped to inspire other African nations to seek independence. It also had a major influence on Pan-Africanism and the Black Pride movements in the United States of America. Ghana is the 7th-best governed country, 5th-most stable country and rated thirteenth-highest HDI on continental Africa. Ghana's economy is the 6th-largest on the Africa continent by purchasing power parity and Nominal GDP and is one of the fastest growing in the world. In terms of purchasing power parity per capita income, Ghana has the highest per capita income in the subregion of western Africa and Ghana has the tenth−highest per capita income on continental Africa. Ghana is one of only five countries in Africa with a free press. Ghana has been a significant petroleum and natural gas producer since December 2010, and one of the world's largest gold and diamond producers, and is projected to be the largest producer of cocoa in the world as of 2015. Ghana is home to Lake Volta, the largest artificial lake in the world by surface area. Ghana's sweet crude oil reserves, ranks at 5th on continental Africa and 21st–25th globally and Ghana's natural gas reserves, ranks at 6th on continental Africa and 49th globally. Ghana ranks as the 61st most peaceful country in the world. Ghana is a regional power in West Africa and on continental Africa, a founding member of the Non-Aligned Movement, and a member of both the Economic Community of West African States (ECOWAS) and the Group of 24 (G24).