t_underbridge

Presumable there's some kind of mortar there holding the bricks together.... I'm not an architect or engineer, so I invite corrections from anyone that's an actual expert, but I doubt even modern mortar could suspend heavy stones horizontally like that -- certainly not for centuries. Real arches are held together by compressive forces. I suppose there could be reinforcement rods inside, but then we should see them protruding in places where the stones have been stripped away. In any event, I think reinforcement rods (rebars) are a fairly recent innovation.

This may have been asked already and my search missed it, but how are those ruined arches in the ancient Engwithan ruins screen shot managing to float in the air like that when they no longer meet in the middle? Is there some in-game explanation? I have to say, it looks a bit silly to me and detracts from the scene.