Q. Which is the only Indus city whose citadel and lower town are together surrounded by its city brick walls?
Answer: Lothal
Notes: Lothal in modern day Gujarat is the only Indus city whose ruins clearly show an outer wall of baked bricks surrounding both its citadel mound and lower town. This indicates organized town planning with a defensive brick perimeter wall to protect the residents. Lothal was likely an important trade center and bead making industry location. The uniform organization of houses, streets, drainage system also tell about their efficient civic administration and governance practiced four thousand years ago.