Enclosure (as in this one as otherwise the prompt is a bit, uh, pointless. :p)

Love stretching across the fence (/veil/some other bordery thing) of death

The troubles of getting into a different country (/kingdom/whatever works for your prompt; the idea is of customs being a gateway, if that helps. I have wording fail.)

Counting sheep (They're supposed to jump over fences as you count them, right?)

Fairy rings