Originally posted by Tom:

Simple answer. No bridge just jump across. Or use a portal to get across, if the enemies break it its easy enough to fix.

I'm leaning heavily in this direction. Just nearby I have one of those freaky stone grave structures. I'm thinking of putting a portal structure on top of it, just as I do with the crypts in the swamp biome. To get metal in and out, well fuggit, I'll use the other realm and a chest exploit.