The National Museum of Technology in Warsaw dates in its present form from 1955, although it has links with earlier collections. It is located in the Palace of Culture, the Soviet-style building that dominates the centre of the Polish capital. It has a comprehensive collection relating to the history of transport, including motor cycles, motor cars and aircraft. Some displays show changes in the household through the twentieth century with the advent of radio and television sets and other electrical appliances. Visitors can make their way through a representation of the underground workings of a Polish coal mine. One of the most prized exhibits is an Enigma coding machine that was used by Polish mathematicians in the early stages of the Second World Wars to break German ciphers. The section on astronomy and space exploration contains many important exhibits, including rockets, satellites and telescopes. There is a substantial collection of musical boxes, and the nineteenth-century Fotoplastikon projects three-dimensional images of important events in the history of technology. The museum has a laboratory where visitors can carry out scientific experiments.The museum manages five branch museums in other parts of Poland.