There are plenty of battles in The Two Towers, what with the Rohirrim's destruction of the orcs who have captured Merry and Pippin, the conflict between Gandalf and Gríma Wormtongue, the pulling down of Isengard by the Ents, the protection of Helm's Deep from all of Saruman's troops, and the fracas between Faramir's men and the Southrons. It packs more action that all four Die Hard movies combined (okay, maybe just the first three).
But in between these pages of huge activity, there are also lots of lengthy descriptions of the surroundings of our heroes. Take, for example, the sudden appearance of the Ents as the Riders of Rohan travel towards Isengard:
Even as [Gandalf] spoke, there came forward out of the trees three strange shapes. As tall as trolls they were, twelve feet or more in height; their strong bodies, stout as young trees, seemed to be clad with raiment or with hide of close-fitting grey and brown. Their limbs were long and their hands had many fingers; their hair was stiff, and their beards grey-green as moss. They gazed out with solemn eyes, but they were not looking at the riders: their eyes were bent northwards. Suddenly they lifted their long hands to their mouths, and sent forth ringing calls, clear as notes of horn, but more musical and various. (3.8.65)
Tolkien describes every aspect of the Ents as they would appear to Legolas and Company: their weird beards, their enormous height, and their solemn eyes. His word portrait of the Ents is so thorough that we can practically see them appearing out of the page. In passages like these, we think that you can really see Tolkien's personal love of words. After all, the guy was an Oxford professor of languages. Of course his descriptive passages would be careful and dense in style. But what we love about passages like these, is that they give Middle-earth a density and realism that you wouldn't expect from a land of sorcery and elves. We want to go to there.