Matthew Poole and continuators on Nehemiah 2:13

13 And I went out by night , by the gate of the valley , even before the dragon-well , and to the dungport , and viewed the walls of Jerusalem, which were broken down, and the gates thereof were consumed with fire.

The footmen which accompanied him directing and leading him in the way. His design was to go round about the City, to observe the compass and condition of the Walls and Gates, that he might make sufficient provisions for the work.

Of which see ch. 3. 13.

A fountain or water so called either from some figure of a Dragon or Serpent which was by it: or from some living Dragon which abode there when the City was desolate: for Dragons delight to be in desolate places▪ and nigh to springs of water, as divers have observed.

Through which they used to carry the dung out of the City.