There were a number of conventional bunkers found, along with some tunnels and underground vaults, some of which were flooded, and a few of which yielded important records, but nothing major was found related to WMD.

A former Iraqi nuclear scientist, Hussein al-Shahristani was a source for the story of the "miles of tunnels," but admitted he had not seen them in person. The technologies for detecting underground voids do not work well in urban areas, so if they were hidden well, they could be hidden for a long time.

As yet, no one has discovered any elaborate far-reaching tunnel network across the country, and unless more evidence is found, I would say they probably do not exist.