The city contains several children's museums as well. The Brooklyn Children's Museum is a general purpose museum in Crown Heights, Brooklyn. Founded in 1899, it was the first museum in the world to cater specifically to children. The museum is currently undergoing extensive renovation and expansion. The New York Hall of Science is a hands-on science and technology center with more than 400 exhibits exploring biology, chemistry, and physics. It is located in one of the few remaining structures of the 1964 New York World's Fair.