A toy building element with transversal openings

A building block unit, comprising one or more first Cross shape part (23,24), the part is a plane inner surface and a plane outer surface; And comprises one or more other Side is part (21,22), which is a plane inner surface and a plane outer surface. Centre part and at least in a corner as and a, so the two inner surface is formed is less than degrees between each. At least on the first Cross shape part (23,24) is provided with a hole (7), the hole piece Side part and penetrates the inner surface of the outer surface, and holes (7) close corner's degree is arranged so: The surface of the second Girder is part (21,22) of the internal surface (4) of with the plane of said first Cross shape part (23,24) of the internal surface (3) is a hole (7). The second Girder is part (21,22) of the internal surface (4) (7) are the distance with a hole, from the hole (7) of the first Side part and inner surface is formed with a crevice.