I was thinking to the Towers, and realized that there was a Tower associated to Fire, namely the Red Mountain, and a Tower associated to Cold, namely the Snow Throat. Besides, there are three fundamental types of destruction magic : fire, frost and shock. From there, a natural question arises : is there a Tower which has the form of a Mountain associated to Thunder or Lightning?

Then I thought to that place in Cyrodiil, http://www.uesp.net/wiki/Oblivion:Cloud_Top. The Ayleid http://www.uesp.net/wiki/Oblivion:Earana%27s_Notes the secrets of the Fingers of the Mountains in an engraved pillar, atop a mountain of the Southwestern Jeralls. Do you think that place could be a minor Tower, and that the Pillar could be its Stone? If not, do you think that one of the Towers is specifically associated with lightning?

Moreover, if Cloud Top is a Tower, would it be too far-fetched to think that http://www.uesp.net/wiki/Oblivion:Earana could have been a Thalmor agent, seeking information on this tower and on the ways Ayleids harnessed its power, in order to destroy it later?

Interesting idea, but I don't think so.