There's also a clue in the other pic... the one with the waterfall and the blue macaws, which then goes back to another clue of blue macaws I posted a while ago. They aren't helpful clues and will probably lead you on a tangent, but whatever.
Well, I remember a Nova or discovery channel story a few years ago about the pirarucu. Giant fish of the flooded Amazon river. But if you say blue macaws were also there I'd have to go with some zoo or tropical gardens as they are now extinct in the wild.
If it's any consolation, this pic reminded me of the one I took while in Yellowstone because of the lighting, and I remembered what you said bout that so I figured at least you'd like this one as well >_>d
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(I have no idea but it looks somewhat eel like)