Recent excavations at Mohenjo-Daro's SD Area have uncovered a massive city wall dating to 2700 BC, along with Kot Dijian pottery indicating earlier occupation. These findings, led by Dr Jonathan Mark Kenoyer, shed new light on the urban planning and defensive structures of the Indus Valley Civilization.
City Wall Discovery and Dating
On 2 June 2026, a mud-brick platform or city wall was excavated 90 cm below the surface on the Citadel mound, west of the Great Bath and Granary. The wall, built with large Harappan mud bricks measuring 10x20x40 cm, was found in trench MD25, Lot 211, Fe 12. Dr Kenoyer noted that the wall's eroded edges require further investigation to determine its original width. The wall's lowest levels have not yet been dated, but the first city wall is estimated to have been built between 2700 and 2600 BC.
The preliminary report of the 2025-26 excavations, prepared by Dr Jonathan Mark Kenoyer, Asma Ibrahim, and Ali Lashari, submitted to the Directorate of Archaeology, Government of Sindh on 16 March 2026, states that Kot Dijian pottery was found in the mortar of the earliest wall, indicating occupation prior to its construction. The report says, "The pottery however provides clear indication of the presence of Kot Dijian occupation prior to the construction of the first mud brick perimeter wall. The samples of mud brick from within the earliest wall also contained small pieces of Kot Dijian pottery that must have been in the mortar used to construct the wall. This indicates that the lowest section of the mud brick city wall dates to the Kot Dijian Period, approximately 3300-2800 BC based on comparative pottery at Harappa and other Sites" (p. 6).
Great Bath and Sacred Tank
The Great Bath, a key structure in the SD Area, measures 39 feet 4 inches on the west side, 39 feet 3 inches on the east, 22 feet 11 inches at the south, and 23 feet 4 inches at the north, with a depth of 8 feet. It was fed by a double ring well in Chamber 16. A thick layer of bitumen waterproofed the tank. The building had multiple halls, chambers, and retaining walls. Evidence of fire, including burnt clay plaster and copper, suggests it was set ablaze during an invasion. According to Mr Mackay, the bath belongs to the Late III and II Phases.
Objects found from the Great Bath during Sir John Marshall's excavation include two phallic emblems in alabaster and faience, a miniature blue faience pot, a copper spearhead, a copper chisel, and seals with animal and pictographic legends, including a horned figure (possibly Gilgamesh) carrying a bow.
Group of Bathrooms in Block 6
Block 6 contains a series of bathrooms arranged in two rows, with a narrow passage and a well-built drain in the middle. The bathrooms vary in size, with narrow doorways and thick jambs. The smallest bathroom is 1 foot 10 inches wide, while the largest is 2 feet 2.5 inches. Mr Mackay described the privacy afforded by the alternating doorways: "The narrowness in conjunction with the depth of the door jambs (some 3 ft. 3 ins) secured a high degree of privacy for the bathers, for no one in the central passage could see into any of the bathrooms without stepping into their doorways." The best-preserved bathrooms are Room 13 (9 feet 6 inches by 5 feet 8.5 inches) and Room 19 (11 feet by 5 feet 6 inches).
Octroi Post and Traffic Control
A brick platform with ten shallow pits, arranged in two parallel rows of five, is located near the Columned Hall in the L Area. Mr Mackay suggested it might have been an Octroi Post or a checkpoint for those entering Main Street. He wrote, "The marked degree to which the surface of this platform is worn between the two lines of holes as compared with the sides strongly bears out this view. A restriction of this kind on the foot traffic down Main Street is comprehensible in view of the character of the buildings in this street."
Buddhist Building and Votive Stupas
Block 8 contains a square Buddhist building with well-defined lanes. Five votive stupas, each about 11 feet 3 inches in diameter, were excavated. They stand on a roughly paved floor, with the tallest being the easternmost at 3 feet high. The walls surrounding the platform appear to be of Kushan date. Antiquities from this block include a hollow pottery monkey, a black steatite head fragment, and a pottery dove with outstretched wings.
Drainage and Water Management
A limestone-covered drain, 12.25 inches wide by 1 foot 4 inches deep, runs along Main Street, sloping south with a fall of 3 feet 6 inches over approximately 350 feet. It received drainage from northern buildings and the Great Bath. The stone blocks average 1 foot 6 inches by 9 inches by 5 inches. Limestone was likely brought from Sukkur, 65 miles away, or from the Khirthar Range.
Housing and Urban Layout
Sir John Marshall classified buildings at Mohenjo-Daro into dwelling houses, undetermined buildings, and public baths. Every family had its own house; the rich had large double-storey houses, while the poor had small ones. Houses were built with sun-dried and mud bricks for foundations, and walls had windows, doors, and ventilators. Individual homes facing side lanes were approximately 15 feet tall. Reed roofs from the Kanai Community were covered with mud mixed with wheat straw. Roofs were flat, accessible via internal stairs, and sloped inward to drain rainwater into house drains.
The ruling class and priestly class likely lived on a mound called RDB Site No. 2, north of the Great Bath. Mr RD Banerji excavated this mound in 1922-1923, finding shrines and structures described in his report.
Conclusion
The excavations at Mohenjo-Daro's SD Area continue to provide valuable insights into the urban planning, defensive architecture, and daily life of the Indus Valley Civilization. The discovery of the city wall and Kot Dijian pottery underscores the site's long history of occupation and its sophisticated infrastructure.
