Grinnell has to be one of the funkiest towns around, I lived there for 4 months during the summer of 1997 and had a blast. The Merchant's National Bank designed by the famous Louis Sullivan has to be one of the highlights of this town. My father actually worked there years after I left town, ironically for about 4 months as well. Weather you pass through, stay forever, or can last only 4 months like a Hyland the town and bank are work checking out.
Photos are from flickr and by Madrid Miner and egami rorrim respectively. Lots more online you should check out. If I could describe the bank better than the journalist who pinned the following in the Grinnell Herald in early 20th century I would, but I can't so here is his recommendation for how to take the building in.
“Go back to the north end and turn around to the south. Raise the eyes above the partitions and brickwork and catch the massive simplicity of the long beams along the ceiling: study the windowed colored by Millet and its mosaic replica below which surrounds the clock with face of gold. Raise the eyes still higher to the skylight… If you are in just the right mood in time you can hear the dash of the waters over Niagara Falls, listen to the winds that sweep across the prairies of the West, see the blue that hovers over the land of the azure sky and understand something of what Sullivan meant when he talked about the genius of America.”