The Brooklyn Children's Museum is a children's museum in Crown Heights, Brooklyn, New York. Founded in 1899, it is the first children's museum in the United States – and according to some, the first one worldwide. It is unusual in its location in what is predominantly a residential area. Housed in a multi-level underground gallery, the museum underwent an expansion and renovation to double its space, reopened on September 20, 2008, and became the first green museum in New York City.