Located on West Madison between Jefferson and Desplaines, and standing more than 100 ft. tall, Oldenburg's Bat Column is quite a delight. And for an interesting look at the site from the 70's before CitiCorp Center was constructed, take a look here.
Completed in 1977, the column is made of core-ten steel (which will never rust beyond it's current state). This close up shows that the intricacy is quite incredible. (And this coming from someone who isn't much of a baseball fan.)
Another close up near the top showing the "hole" at the end of the bat.
I once again want to send out many thanks for the positive feedback. I have received many e-mails of support, and look forward to many more posts ahead!