Lake Mead is now the 28th largest man-made lake reservoir. Lake Kariba in South Africa is the largest. The dam, which was actually built in Black Canyon instead of Boulder Canyon as originally planned, was called both Boulder Dam and Hoover Dam interchangeably for years, but the name Boulder Dam never really caught on and Hoover Dam, named after the US president at the time construction was begun, became the official name in 1947, and is how it is known to the world. The Hoover Dam is currently 28th in line for the tallest, 18th in line for concrete construction dams, and 63rd for generating electricity.