The St Louis Arch is an amazing structure. Huge, steel, magnificent piece of art. The little white pod that takes you to the top is small (you feel like you were shoved in a pea pod with 4 other people) and kinda rickety but you just HAVE to do it anyways. Once your up there, it's hot and stuffy and the thing sways so you don't stay too awfully long. But the view, the view, is so worth it. After we came down our micro pea pod, we explored the museum under ground. It is chalked full of history about Lewis and Clark, the settling of the West, and was more than any one person can take in. This was a highlight for me. Another thing I can check of the list.
St Louis Arch. Check.