The flight cage at the St. Louis Zoo was built by the Smithsonian Institution for the Louisiana Purchase Exposition, the 1904 world's fair. Slated to be taken to Washington at the close of the fair, the people of St. Louis worked to keep it. They have a strong history for getting and keeping public spaces.
The flight cage became the first exhibit of a new zoo after the close of the fair.
The present exhibit is a cypress swamp and is a lovely, quiet, contemplative outpost at the Zoo. There are beautiful tile pictures of birds in swamplands at the entrance of the Flight Cage, which I will feature in another post.