A massive underground city loomed before me, lit up with millions of tiny lights, gleaming yellow, blue and green like a blanket of stars. From where we floated in the black waters of the lake, I could see large stone buildings, streets winding upward in a spiral pattern and ice covering everything. The cavern above soared into darkness, farther than I could see, and the twinkling lights made the entire city glow with hazy etherealness.

At the top of a hill, casting its shadow over everything, an enormous, ice-covered palace stood proudly against the black. I shivered, and the knight behind me spoke for the first time.

“Welcome to Tir Na Nog.”

In The Iron Daughter, Meghan is Mab’s prisoner and has no idea how long she might be there or what Mab plans for her. This is her description of the throne room when Mab first calls for her in Daughter:

The corridor ended, opening up into a massive room with icicles dangling from the ceiling like glittering chandeliers. Will-o’-the-wisps and globes of faery fire drifted between them, sending shards of fractured light over the walls and floor. The floor was shrouded in ice and mist, and my breath steamed in the air as we entered. Icy columns held up the ceiling, sparkling like translucent crystal and adding to the dazzling, confusing array of lights and colors swirling around the room. Dark, wild music echoed through the chamber, played by a group of humans on a corner stage. The musicians’ eyes were glazed over as they sawed and beat at their instruments, their bodies frighteningly thin. Their hair hung long and lank, as if they hadn’t cut it for years. Yet, they didn’t seem to be distressed or unhappy, playing their instruments with zombielike fervor, seemingly blind to their inhuman audience.

On the far side of the room, a throne of ice rose into the air, glowing with frigid brilliance. Sitting on that throne, poised with the stillness of an approaching glacier, was Mab, Queen of the Unseelie Court.

Other notable regions in Tir Na Nog:

Glassbarrow

Glassbarrow is a mountainous region in the Winter Realm, far removed from the court, and ruled over by an Ice Baron, known as the Duke of Glassbarrow. The mountains in this territory are inhabited by deadly ice wyrms.

The Ice Maw

The Ice Maw is a great chasm that separates the wyldwood and the Winter Realm. It runs for miles in either direction, meeting the Wyrmtooth Mountains in the north and the Broken Glass Sea in the south. The Ice Maw could at one time be crossed using an arched ice bridge, but this was destroyed by Prince Ash while being hunted by Wolf.

The Chillsorrow Manor

The Chillsorrow Manor is a sprawling estate blanketed in ice and snow. Inside, the stairways are slick, the floors resemble ice rinks and the air is frigid cold. The manor is served by creepy, pale-skinned, skeletal gnomes.

Even more wintery regions: