I love the signage associated with early 20th-century European metros. One of the coolest things about them is the lack of consistency from stop-to-stop. Often, each stop has a design associated with the location and the era that neighborhood first became hot. Many new train lines all around the world try to embrace this concept but the ones that developed organically — like Paris and Barcelona — are unique in that the signage is authentic because it was actually created at the time the neighborhood earned it... rather than being awarded the honor half a century later.
This photograph was captured with a Nikon D90.