Abstract: The border blocks of the invention include a plurality of hollow plastic blocks fillable through push-cap openable holes at their top with sand and employing various tongue-and-groove interlocks extending from the left and right sides thereof to join with similar adjacent blocks--whether linear or curved--and with the individual blocks also being provided with apertures at their bottom to mate with projections as part of the push-cap openable holes so as to stack one atop the other in forming several courses of block and in which the blocks forming the bottom course incorporate a tie-down arrangement for securement to the ground.