Abstract: An arcuate structure containing at least sixty six-sided building blocks, and said six-sided building blocks are independently able to provide means for connecting one of said six-sided building blocks to at least one of said six-sided building blocks. The outside face of the six-sided block has a substantially rhomboidal shape, and is substantially parallel to the inside face of the six-sided block. The right edges and the left edges have equal lengths and form equal angles with the inside face and outside face. The left and right sides of the six-sided block are congruent with each other, are in the shape of a parallelogram, and contain two recesses and two projections within their borders.