(This requires ¹  a mind that has wisdom.) The seven heads are seven mountains ²  the woman sits on. They are also seven kings:

Now ¹  this is what the horses and their riders ²  looked like in my ³  vision: The riders had breastplates that were fiery red, ⁴  dark blue, ⁵  and sulfurous ⁶  yellow in color. ⁷  The ⁸  heads of the horses looked like lions’ heads, and fire, smoke, and sulfur ⁹  came out of their mouths.