Building toy system with basic element and connecting pin

A building toy comprising:

• at least one basic element (1),
• at least one independent connecting pin (3),
• wherein the basic element (1) has a body having at least three adjacent walls (7), each one of the walls (7) is perpendicular to the corresponding adjacent walls forming an internal cavity on the body, each one of the walls (7) includes a pair of connecting openings (2) located side by side to each other and wherein of a line connecting axes of the pair of connecting openings (2) is located in a center of the wall (7) being symmetrical through the middle of the wall (7), wherein each one of the pair of connecting openings (2) on each wall are located on a different plane, wherein each one of the planes are perpendicular to each other and intersect in a center of the basic element (1),
• wherein each one of the connecting openings (2) are placed in a middle central line of the corresponding wall and the middle line is parallel with an edge of the basic element,
• wherein each one of the connecting openings (2) run through the internal cavity of the body from one of the walls to the opposite wall, forming a transitory cavity,
• wherein each one of the transitory cavities of the connecting openings (2) is mutually avoided without mutual interference with regards to the other transitory cavities,
• a connecting pin (3) inserted to each one of the connecting openings, each one of the connecting pins (3) connects the basic element (1) with a second basic element of the building toy, and
• wherein a profile of each one of the connecting openings (2) is independent and without an intersection with the profile of the other connecting openings (2) in the body.