[Citizen Tom Paine]

I thought that Jericho was the oldest walled city.

[lexington minuteman 1775]

Yes, I think you are right about Jericho, but could not be much older than 9,000 years. Anybody in FREEPERLAND know?

[CobaltBlue]

Jericho is defined as an extremely old "settlement", but not a "city" like Harappa or Mohenjo-Daro.

Jericho = 40,000 sq. meters, a few huts.
http://en.wikipedia.org/wiki/Jericho

Mohenjo-Daro = 30,000 - 40,000 residents, many square miles.
http://en.wikipedia.org/wiki/Mohenjo-daro

Indus River Valley civilization:
http://en.wikipedia.org/wiki/Indus_Valley_Civilization