The third, fourth, fifth and last pics are all from Mashhad.
The second and sixth pics are from Isfahan.
7th and 8th are from Tabriz.
9-12 are all from Kermanshah(with a handfull of kurds, if not most are kurds, not sure)
13 and 14 are from Mazandaran
15, 16 and 17 are from Tehran
18 is from Abadan, Khuzestan
the women at 19 are from Kerman
the men at 20 are from either Shiraz or Kerman
Im not sure where the first pic is from, but looking at the nature in the background, its likely around Mazandaran or Isfahan.