@Summer Tanager yep, it's a nest. They had the area directly in front of it and around 3ft roped off to keep people from getting right in front. It was a really nice crane habitat.
@SwampDonkey Thank you for replying! That's great news about the cranes nesting on exhibit, and I'm very happy that the zoo took some precautions like roping off the area in front of the nest to help the cranes!