Five settlements that exist because a government or a power company needed to put thousands of construction workers somewhere near a river — and that outlived the pour of concrete they were built for.
Built in 1931 by the Bureau of Reclamation to house the Hoover Dam workforce, planned by Saco Rienk de Boer. Gambling remains illegal, as in Panaca; alcohol was legalised in 1969. Lake Mead is the largest reservoir in the US by capacity.
Founded in 1968 by CESP to house the builders of the Ilha Solteira Dam on the Paraná (3,444 MW, one of Brazil's largest). UNESP has had a campus in the former company town since 1976.
The Akosombo Dam (1961–65) created Lake Volta, 8,500 km², the largest reservoir by surface area. Kwame Nkrumah opened it in January 1966 and was deposed in February. The Valco smelter at Tema was built by Kaiser Aluminum.
The Kariba Dam (1955–59) on the Zambezi created Lake Kariba, 280 km long, between Zimbabwe and Zambia. Operation Noah rescued about 6,000 animals. The kapenta fishery was stocked from Lake Tanganyika in the 1960s.
Built from 1957 for the builders of the Krasnoyarsk Dam on the Yenisei (6,000 MW, completed 1972); the dam is on the 10-rouble note. The ship-lift is the only one of its kind in Russia. The Yenisei stays unfrozen below the dam all winter.
Think you'd have found them? Play today's expedition, or replay this one from the archive.