Abstract: A paving block (10) has substantially parallel top and bottom surfaces, is based upon hexagonal geometry and has a central portion (10a) which is a substantially equilateral triangle and three portions (10b) (herein called apex portions) Each apex portion is located in the region which would otherwise be the location of a respective apex of the triangle. Each apex portion has a first pair of walls (17) each of which in part defines a boundary of one of three recesses in the block and a third wall (17c) which defines an outer boundary of the respective apex portion. The third wall is shaped to secure an interfit between a recess of one block and an apex portion of an adjacent similar block, the interfit being incomplete and arranged to define one of a plurality of water run-away holes (20) in an array of laid blocks.