From A Wiki of Ice and Fire
The night before the planned attempt to scale the Wall, Jon tells Ghost that he cannot come with him, and that they will meet again at Castle Black. The Magnar forces Jon to tell him more about the patrols the Night's Watch use along the Wall. Jarl and Styr plan to climb the Wall between Stonedoor and Greyguard, where a hill rests against the Wall, making for a shorter climb. Later, Jon and Ygritte spend time in a cavern which supposedly leads from the Haunted Forest all the way beneath the Wall and beyond, but no one since Gendel and Gorne, the legendary wildling twin kings, knows the way. As they make love, Ygritte asks Jon to stay with her and hide in this cavern forever.
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