Abstract: The invention relates to a toy building block system (100) comprising one or more building blocks (200); and one or more wheels (300); wherein each said building block (200) comprises: a first elongate portion (2) extending in a longitudinal direction (X); a second elongate portion (4) extending in said longitudinal direction (X); an intermediate portion (6) connecting said first elongate portion (2) with said second elongate portion (4) at a middle position (8) thereof; a first end portion (10) extending in a transverse direction (Y), perpendicular to said longitudinal direction (X), from said first elongate portion (2), at a side thereof opposite to said intermediate portion (6), and at a middle position thereof; a second end portion (12) extending in said transverse direction (Y), perpendicular to said longitudinal direction (X), from said second elongate portion (4), at a side opposite to said intermediate portion (6), and at a middle position thereof; said building block thereby comprises six protrusio

Abstract: A building block system includes one or more building blocks and one or more wheels, each building block including a first elongate portion extending in a longitudinal direction, a second elongate portion extending in that longitudinal direction, an intermediate portion connecting the first elongate portion with the said second elongate portion at a middle position thereof, a first end portion extending in a transverse direction, perpendicular to that longitudinal direction, from the first elongate portion, at a side thereof opposite to the intermediate portion, and at a middle position thereof. A second end portion extends in that transverse direction, perpendicular to the longitudinal direction, from the second elongate portion, at a side opposite to the intermediate portion, and at a middle position thereof. It thus includes six protrusions and two voids, each void defined between an end of the first elongate portion and an end of the second elongate portion.