After watching The Lord of the Rings trilogy, viewers may be left wondering what, exactly, the titular two towers are in relation to Middle-earth’s dense history and lore. The structures are important enough to be referenced in the subtitle of the trilogy’s second film, The Lord of the Rings: The Two Towers. In adapting J.R.R. Tolkien’s novel of the same name, The Two Towers chronicles three storylines: Frodo and Sam’s One Ring-destroying journey toward Mordor; Merry and Pippin’s meeting with Treebeard the Ent; and Aragorn, Legolas, and Gimli’s run-in with the fractured kingdom of Rohan.

https://screenrant.com/lord-of-the-rings-two-towers-title-meaning-explained/