The construction of the hydroelectric dam on the River Volta near the city of Akosombo in south-eastern Ghana led to the creation of the biggest man-made lake in the world. The plant provides electricity and water to the whole of Ghana and to neighbouring countries such as Benin and Togo. Plans for the project were drawn up in the 1940s, when Ghana was under British rule. The project for a dam on the River Volta was developed after the country gained independence, in 1961, thanks to international funding, in order to sustain the country's economic and industrial development, which previously relied exclusively on coffee production. The project involved the construction of two rockfill dams with clay core and was completed in 1966. The main dam has a maximum height of 134 metres and a crest length of 670 metres.