The gist of what I'm getting from people's comments is something like an outer promenade with its outside walls made of glass. The inner wall would be solid and at the center(inside this wall) would be where the display areas are. It may be cool to have the top-most level completely encased in glass to house a local, 'natural' exhibit.
disclaimer: My gist may have myst because I lurk on this list.
Exactly right

This allows the public to break the mood attatched to each room by stepping out of the galleries to the promenade and viewing the jungle. It's like a cracker or swill of water after a wine tasting. Vagwen... your picture is right on the money. As long as the windowed hallway doesn't end and continues around the corner.
I haven't had time to do my own sketch
I also like the idea Vagwen has for the wall colour. That hue of purple in nearly neutral... i like it a LOT
