Abstract: A modular barrier and restraint for children or infants. The device has several interchangeable pieces, including substantially elongated barriers, rectangular end pieces, pyramidal end pieces, and castle end pieces. This interchangeability allows a one-dimensional, two-dimensional, three-dimensional, or four-dimensional barrier. Each piece is fitted with either a slot or counter slot to be fitted together to easily form the barriers. Holes may be placed through the pieces to form a handle. Other holes may be placed into or through the pieces to either provide a place through which a child or infant can see or into which a mirror can be placed.