I think that may be an optical illusion. It looks to me like there's still a wall at the low point. But I've never been there of course so that's just how it appears to me from the photo.
I think that may be an optical illusion. It looks to me like there's still a wall at the low point. But I've never been there of course so that's just how it appears to me from the photo.
It was more of a short ledge, only enough to prevent the hippos from over-stepping the ledge by mistake but can't stop them from falling. I think the enclosure employs a psychological barrier with its sheer drop.