The Harappan civilization was marked by extraordinary uniformity in artefacts as evident in pottery, seals, bricks and weights. The majority of cities were constructed in a highly uniform and wellplanned grid pattern, suggesting they were planned by a central authority. This uniformity went missing in the Late Harappan period. Town planning was abandoned, and public buildings fell in ruin. Distinctive artefacts of the civilisation- weights, seals, special beads, writing, longdistance trade, and craft specialization disappeared during this period. House construction techniques deteriorated, and large public structures were no longer produced.