I live in the San Francisco Bay area, a center of varied geology and significant geologic history. If you travel enough, one day you'll be laid over in some airport city for a day. What if it were here? Sure you could party with local friends, but you could also take those friends with you on a field trip!
Now I could make a huge list, but it's easy to find on my site and I'll spare you. I think it would be more interesting to know about YOUR city. Post a comment or submit a post to the collection.
(Oh, OK, here's my California Geology stuff.)