It’s not exactly an obsession, but one of the things I look for when we travel (other than lighthouses and covered bridges) is train stations.  They are generally very easy to spot, as their architecture tends to be quite unique.  They are usually, but not always, located next to railroad tracks.  Sometimes they are still active passenger depots, but more often than not have been converted to offices, civic centers or meeting halls.  I’ve seen some that are police stations, city halls and even restaurants.  Most heartbreaking for me is when I see one in disrepair.  It takes a lot of money to keep these places up, but they are an important part of history and I love to see them being used and maintained.