Anubis
No Lifer
I don't think the show has done a great job showing just how vast the wall is (or how large Westeros is, for that matter).
when John climbed it in season 3 they did a pretty freeking good job of saying how big it was.
he also said keeps were manned still
East watch
Castle Black
the Shadow Tower
now he may have been lying about that as he also told them castle black had 1000 people at it
pretty sure they have said its about a months journey from Winterfel to the wall more than once