From The Doll's House: Volume 2 in the Sandman Series:
"There is only one thing to see in the twilight realm of Desire.
It is called the threshold. The fortress of Desire.
Desire has always lived on the edge.
The threshold is larger than you can easily imagine. It is a statue of Desire, him-, her- or it-self.
(Desire has never been satisfied with just one sex. Or just one of anything - excepting only perhaps the threshold itself.)
The threshold is a portrait of Desire, complete in all details, built from the fancy of Desire out of blood, and flesh, and bone, and skin.
And like every true citadel since time began, the threshold is inhabited.
There is only one occupant, at this time.
Desire of the Endless.
The threshold is far too large for just one person.
It contains two eardrums larger than a dozen marble ballrooms.
And empty, echoing veins, like tunnels. You will walk them until you grow old and die without once retracing your steps.
Given Desire's temperament, however, there was only one place in the cathedral of its body to make its home.
Desire lives in the heart."
- Neil Gaiman