Abstract: The present invention includes: a base section configured such that, taking the unit edge length D1 to be 1 and a cube expressed as 1×1×1 to be one unit size, the base section has a parallelepiped shape in which one or more 1-unit sizes are conjoined, and is composed of an open, hollow face taken to be the bottom, four lateral walls 3B, and a roof 3A; and cylindrical projections having a cylindrical shape and provided on the outer face of one or more of the roof 3A and the lateral walls 3B, with a diameter D2 being equal to or greater than 0.4 but less than 0.6 with respect to the unit edge length D1, and a height being (1?diameter)×(0.4 to 0.5 inclusive).

Abstract: By a combination of a plurality of blocks 11 in which a plurality of projecting portions 37 which are formed into the same cylindrical shape are provided on an upper surface of a rectangular parallelepiped base portion 31 at intervals of several millimeters, the base portion 31 has a rectangular parallelepiped interior space which is made to open downwards so as to enable the accommodation of projecting portions 37 of other blocks, and the cylindrical projecting portions 37 of the other blocks are made to be held by side wall panels 33 of the base portion 31, a drawback that the change in shape of a shaped structure becomes less conspicuous is eliminated irrespective of a reduction in the number of types of blocks with respect to their shapes.