One thing I love about Tolkien is his mastery of description. Take, for example, my favourite paragraph in the whole trilogy:
“A long-tilted valley, a deep gulf of shadow, ran back far into the mountains. Upon the further side, some way within the valley’s arms, high on a rocky seat upon the black knees of the Ephel Duath, stood the walls and towers of Minas Morgul. All was dark about it, earth and sky, but it was lit with light. Not the imprisoned moonlight welling through the marble walls of Minas Ithil long ago, Tower of the Moon, fair and radiant in the hollow of the hills. Paler indeed than the moon ailing in some slow eclipse was the light of it now, wavering and blowing like a noisome exhalation of decay, a corpse-light, a light that illuminated nothing.”
— “The Stairs of Cirith Ungol”, The Lord Of The Rings: The Two Towers.
Okay, people mutter about Tolkien taking three pages to describe a field of flowers (which to my mind is gross exaggeration – if anyone can find me the relevant passage I’ll happily stand corrected,) but this single paragraph tells us a lot. It sets the atmosphere: dark, grim, spooky. It shows us where Sam and Frodo are in their journey: they’re moving from the woods of fair Ithilien to a more dangerous path. It tells us a little of the history of Gondor and the spread of Mordor’s evil: this tower didn’t always belong to the enemy.
In short, it balances setting, backstory, and plot with deceptive simplicity. It shows us the immediate setting, alludes to the backstory, and moves the plot forward – all in one short paragraph.
Besides which, the tone of it is exquisite. That last sentence gives me shivers every time I read it.