The Great Wall
The largest man-made structure in the world, the Great Wall was built by the Dusk Empire to keep out the Fomorian hordes of the North. The Wall is roughly 20 feet thick and 200 miles long with only about 12 gates across all this distance. The Wall stands roughly 40 feet tall with 80 foot towers every mile. A railway train runs across the length of the wall thar allows for swift travel within the walls borders along the wall.