Semir Osmanagic discussed how each concrete block is a different size and shape, and how this structure is similar to pyramidal structures in Cuzco, Peru. He suggests that a potential benefit of having a structure with different sized and shaped blocks is to help with structural stability; blocks of this sort would lock themselves in as opposed to collapsing during, for example, an earthquake.
Osmanagic also talks about how the spaces between the blocks go all of the way to the inside of the pyramids, and how these gaps possibly served to collect water and to ventilate the air. He also speculates that the reason that there two layer blocks on the pyramids (the base being completely flat and the top being wavy and textured) is that, “whoever designed these blocks wanted a wavy texture on the top.” In general, there are two types of blocks, each with a different look – one block looks like a monolith line of concrete and the other block looks like construction plates with clear edges and sides.
Although the construction of the Bosnian Pyramids in Visoko, Bosnia and Herzegovina is not entirely known, there seems to be evidence pointing towards the idea that the material used to build the pyramids is an extremely advanced form of man-made concrete with unique properties. Perhaps research done by volunteers of the “Archaeological Park: Bosnian Pyramid of the Sun Foundation” over the summer of 2015 will tell us more..
(Source: bosnianpyramids)