GC, you are correct! The Arch itself is only one physical use, well 2. The first one is that you can go up in it and look out. The 2nd is that lil red light on the top guides planes up higher to avoid the buildings in downtown STL. But under the Arch there's the museum of Westward expansion, and around the arch there's river boats and fairgrounds.
Some other things in STL:
The Moonlight Ramble, world's largest after-dark(starts at midnight) bicycle marathon(you could make it a slow paced ride, keep up with the masses, or go plowing ahead over sidewalks and stuff, like me and a friend did this year(Aug 13th or somewhere around there). It's a 15 mi ride through downtown STL, the Police set up road blocks to prevent cars from driving where riders are(although I had a really close call with an Explorer that found it's way around the police and was driving towards our pack in the opposite lanes...I had to swerve right, the pack was so dense that I was stuck past the double yellow line, doing about 30mph(while the Explorer was going probably 35-40), and I almost was hit)and there are refreshments at the end and other stuff. It's fun, and the money goes to charity.
NBC Newschannel 5, most watched newscast in the nation(I watch it, much better than Fox or CBS or ABC).
And STL also has a vast variety of social classes, from the homeless roaming around downtown, to millionares in huge estates in West STL county(in counties like Claton, Ladue, Manchester, and Kirkwood, among others)
There's also a lot of different ethnic groups here.
The Dred Scott court case happened here.
There's been 1 or 2 100+cars in pileups here.
the STL Autoshow is pretty big.
There's also the Motorcycle show
And foods like ribs, and grilled stuff.
And there
were like 7 Go-cart places here...the closest closed up this year, another closed up a while back, then re opened and then closed again, and several others that are gone. The only good one left is Boscher Town, a huge streched out track, old as dirt, the track surface is smooth(from flooding, it's right near the MO river), and the cars aren't electronicly controlled, so you could virtually keep driving forever but you would probably be banned from the place. They are old chassis, little circle pedals, and no body work at all. Very fun, especially if you are like me or my bro, who would push the other while the one in front had the tire locked up, leaing a huge skid and smoke lol.
We also have the Katy Trail, a biking/walking trail...goes from STL to independance MO(I think), some 300+ miles, which my bro(and this class) rode several years ago, in like 3 days or so.
And we have a lot of Casinos here too.
Art Museum(been there, boring stuff)
Children's museum(been there, fun stuff like a roller slide(made of conveyerbelt rollers), serious speed down that. Also a tunnel that leads to a climbing thing with branches and stuff, and a huge fishtank, if you can find it though the tunnels and stuff.)
Car Museum(been there, a long time ago. Fairly close to here, right by a Churches Chicken

. I want to go again soon, they had a wide variety of model cars.)
Airshows
The Magic House(fun stuff too)
The Science Center!! How did I forget?! Lots of fun stuff, from taking radar over highway 40(there's a bridge that connects the old part of the science center to the new part, over the highway. They also have the Omnimax theater, showing IMax movies on a huge dome screen that goes above your head and down to the floor, it's amasing...they show you flying over the Serengetty, you feel like you are flying(some parts can get really dizzying, they tell you to look away or close your eyes if you get dizzy). It's awsome. There's interactive medical exhibits, structural exhibits, aviation exhibits, space, everything really. An exellent place to spend a day.
I guess STL is full of stuff...