They chain the buildings to the concrete, to keep them from blowing off in high winds. In some cases, with the taller structures, they use actual nautical chain that's used for huge anchors. It's very impressive.
Looking down over the edge, into the valley a mile below.
On the way home we stopped here, at Glen Ellis Falls--not as impressive, perhaps, as Arethusa, but the walk down in is even steps, and I managed the whole gig without whining. In itself, no mean feat.