Revelation is full of SEVENS and says:
“Here is the mind that has wisdom; The seven heads are seven mountains, on which the woman sitteth. And there are seven kings....And the ten horns which thou sawest are ten kings, which have received no kingdom as yet..."
“And the 10 horns out of this kingdom are 10 kings that shall arise: and another shall rise after them; and he shall be diverse from the first, and he shall subdue 3 kings.” (Dan 7:24)"
7 of 10 kings will be left. Rome sits on 7 mountains, and the names of these 7 mountains (Aventine, Caelian, Capitoline, Esquiline, Palatine, Quirinal, Viminal) bears a strong relationship to the names of the 7 Cities of Asia, something discussed in detail in "Unveiling the Hebreek Meaning of the 7 Cities of Revelation" . The connection is so strong, that the connection between their names and geography suggests to me that the False Messiah will remove one of the 10 kingdoms and give it to one of the 7 kings, and will remove 2 kingdoms to give to another of the 7 kingdoms. And I think that someone could probably map the names of the 7 cities to the 7 kingdoms that will remain at the end times if they are alive when it happens and thus figure out what those 7 kingdoms are.
Note that Rev 17:9 starts by saying, "Here is the mind that has wisdom." It does not say that the symbolism is impossible to decipher. It simply says it takes wisdom to decipher it. I believe the names of the 7 cities map to these 7 hills and 7 kings and holds the key to understanding the type of "wisdom" that Rev 17:9 is talking about.
The video at http://www.messiahalive.com/The7Cities.htm explains the basic roadmap while the book delves into this topic in probably as much pre-event depth as possible before events trigger to suggest the 10 kingdoms are here.
If the above video fails to play, click on http://www.messiahalive.com/The7Cities.htm and watch it there.