Children were racing around a patient tree, an exasperated parent or a bewildered dog; sweethearts framed their loved-ones in their embrace; joggers... jogged.

It's a joy to watch people interacting with the willow herd. In particular, I'm fascinated by how we all approach them. The scientists zoom in with their camera lens on to a particular feature - the tip of the trunk, say, or the tail - to examine the willow. Artists sidle up to the elephants at very peculiar angles and loiter for longer.

But the rest of us, the majority of passers-by, with lots on our mind, walk straight up to the side of the elephants. We slap their flanks as if expecting them to stamp their foot and snort in response. Then we fiddle with their ears and stroke their trunk. Some of us can resist no longer and throw our arms around them in our blissful smile of infancy - which, I now know, never completely disappears.

Goodness only knows what the elephants think... but, of course, they're willow and don't think at all... although... as we were leaving, I felt sure I heard a muffled chorus of "Don't Stand So Close To Me" coming from the direction of the herd.