Many of the Harappan cities were divided into two or more parts. These were:
(i) The part to the West was smaller but higher, and the archaeologists described this as the citadel.
(ii) The part to the East was larger but lower, known as the lower town.

Seals may have been used to stamp bags or packets containing goods that were sent from one place to another.
After a bag was closed or tied, a layer of wet clay was applied on the knot and the seal was pressed on it. The impression of the seal is known as a sealing.

Various objects that were made and found in Harappan cities were:
(i) Most of the things that have been found in Harappa by the archaeologists are made of stone, shell and metal, including copper, bronze, gold and silver.
(ii) Copper and bronze were used to make tools, weapons, ornaments and vessels. Gold and silver were used to make ornaments and vessels. Perhaps the most striking finds are those of beads, weights and blades.

In Harappan civilisation, usually houses were either one or two storeys high, with rooms built around a courtyard.
Most houses had a separate bathing area and some had wells to supply water. Apart from these, Harappa had elaborated storehouses.

Metals, writing, the wheel and the plough were important for the Harappans as:
Metals
Archaeologists have found things made of metal, including copper, bronze, gold and silver in Harappan cities. Copper and bronze were used to make tools, weapons, ornaments and vessels. Gold and silver were used to make ornaments and vessels. So, these were important for the Harappans.
Writing
There were scribes, people who knew how to write, they helped to prepare seals, kept a record and wrote on other materials that have not survived.
Wheel
It played a great role in the life of Harappans. For example
(i) People could travel long distances easily.
(ii) Goods were carried easily from one place to another.
Plough It was used to dig the earth for turning the soil and planting seeds.

Archaeologists know that people in the Harappan civilisation used cloth because they have found pieces of cloth attached to the lid of a silver vase. They have also found spindle whorls, made of terracotta and faience, which were used to spin thread. Moreover, a stone statue of a man wearing an embroidered garment was found in Mohenjodaro.

(i) Above picture refers to beads.
(ii) Many of these were made out of carnelian, a beautiful red stone.
(iii) A hole was bored through centre so that a string could be passed through it.

(i) The Great Bath of Mohenjodaro
(ii) It was constructed by bricks and coated with plaster.
(iii) Harappan cities
(iv) (a) There were steps leading down to bottom.
(b) Water was drained out after use.

Reasons for the fall of the Harappan cities were:
(i) Till date, no concrete reason has been found out by the scholars, but some of the scholars suggested that the rivers dried up.
(ii) While other scholars have suggested that there was deforestation because large quantity of fuel was required for baking bricks and for smelting copper ores.
(iii) Besides, grazing by large herds of cattle, sheep and goat may have destroyed the green cover. In some areas there were floods.
(iv) But none of these reasons can explain the end of all the cities since the flooding, or a river drying up would have had an effect in only some areas.
(v) Some sites in Sind and West Punjab (present-day Pakistan) were abandoned, while many people moved into newer, smaller settlements to the East and the South, it seems as if the rulers lost control over their subjects.

In some cities, special buildings were constructed on the citadel. In Mohenjodaro, a very special tank, which archaeologists call the Great Bath, was built. This was lined with bricks, coated with plaster and made water-tight with a layer of natural tar. 
There were steps leading down to it from two sides, while there were rooms on all sides. Water was probably brought in from a well and drained out after use. Perhaps important people took a dip in this tank on special occasions.

Many of the Harappan cities had covered drains. These are as follow:
(i) We can notice how carefully these were laid out, in straight lines. However, each drain had a gentle slope so that water could flow through it.
(ii) The drains in houses were connected to those on the streets and smaller drains led into bigger ones.
(iii) As the drains were covered, inspection holes were provided at intervals to clean them. All three - houses, drains and streets - were probably planned and built at the same time.