The Wall is what protected the Seven Kingdoms from the North of Westeros. It is around three hundred miles long and around seven hundred feet tall. It's entirely made of ice and stands since thousands of years. It's really impressive. And when you stay on top of it, you get the impression that you are standing on the top of the world.

[Whenever Tyrion thought about the wall, he also thought of Jon Snow and their journey together to the wall.]

Brave men serve there to protect the Seven Kingdom from what lives in the North.

[Tyrion thought that it was better to refer to everyone in Castle Black as 'brave men' instead of saying what they really were. But he had seen them and when he thought about what they were going to fight against, it was just right to say that they were 'brave men'. Perhaps the bravest ones in Westeros.]