Originally posted by Agent Elrond
def Orthanc and it's either Barad-dur or the Tower of Cirith Ungle. Both work
... still, the book cover clearly shows Orthanc and Morgul.
as taken from the back of my Two Towers book:
"The Cover of this new edition of the Two Towers is based on Tolkiens own unused Sketch of 1954. It shows the One Ring above Mount Doom, flanked by the towers of Minas Morgul and Orthanc, while above it flies a Nazgúl. The Tengwar inscription in the center reads "In the land of Mordor where the Shadows Lie". At the base of Minas Morgul are the nine rings of the Ringwraiths, while above it a cresent moon hints at the earlier name of the tower, Minas Ithil, Tower of The Moon, before it was taken and defiled by Sauron's Forces. Above and beneath orthanc, a wizards pentacle and a white hand symbolize the influence of Saruman"
So yeah, Orthanc and Minas Morgul/Ithil. Hope I havnt repeated anyone, but yeah 😛
To quote the final passage in The Fellowship of the Ring
" The second part is called THE TWO TOWERS, since the events recounted in it are dominated by ORTHANC, the citadel of Saruman, and the fortress of MINAS MORGUL that guards the secret entrance into Mordor..." (emphasis theirs) therefore it is quite clear which two towers Tolkien had in mind...
Nope, not at all.
The problem is, Tolkien made SEVERAL drawings, with different Towers in each. That section at the end of FOTR was added in later, I think, and not by Tolkien. Tolkien himself was never clear on the matter:
"The Two Towers gets as near as possible to finding a title to cover the widely divergent Books 3 & 4; and can be left ambiguous- it might refer to Isengard and Barad-dur, or to Minas Tirith and B; or Isengard and Cirith Ungol (1)." [Letter #140]
and
"I am not at all happy about the title `the Two Towers'. It must if there is any real reference in it to Vol II refer to Orthanc and the Tower of Cirith Ungol. But since there is so much made of the basic opposition of the Dark Tower and Minas Tirith, that seems very misleading." [Letter #143]
So he didn't know, so nor can we ever be clear. The original responses to this thread were right; the attempts to pin it down later have been misleading.