@TinoPup adequate water, shade and sun areas, mud and hard parts, and a good amount of land area as well, not to mention parts where they can be more private. The whole enclosure is a good size too.
@TinoPup I guess you have to compare pictures and what you have seen in person.
In this case the size is better than many others that I have seen, the way the habitat is divided in different spaces works great, the water feature is both nice looking and usefully designed, and they have a mud area in addition to the water. It may not be quite as spacious as Jackson Zoo, but it looks far superior from a visitor standpoint and it has led to breeding success already.