Gentoo Penguin colony at Edinburgh Zoo 2008

Perhaps the designers of this exhibit were under the impression Penguins came from the moon..?

NZ Jeremy: regardless of the exhibit, it is one of the UK's most successful (if not the most) penguin groups.

A case of practicality over style...

This is one tiny part of the enclosure that although has concrete for ease of cleaning also has grass/planted areas, loose pebbles etc and is much more like their natural environment on sub-Antarctic islands that many indoor penguin enclosures that seem to suggest that all penguins live only on ice and snow. It also provides nest rings for gentoos penguins in a manner that replicates the natural inclination of the gentoo to nest in colonies, close together and provides them with pebbles as nesting material, as this is what they use in the wild.
As CZJimmy says, the most successful breeding group of gentoo penguins in Europe and if you are in New Zealand, they also supplied all the gentoo penguins that started the Kelly Tarltons group.
The photo really doesn't do the enclosure justice and looks aren't everything, I would much rather see the penguins displaying all their natural behaviours (on land and in their pool) than see them sitting around on ice all day.