Hidden Alleys

The alley pictured above lies between two commercial buildings in Portland, Maine. I snagged a picture of it because it struck me as somehow alien. Certainly there are tosn of alleys between tons of buildings in tons of cities, but I've never seen one so nondescript, clean, and devoid of any inhabitants or stuff. It's totally empty, and has no lighting sources, so it's completely dark at night. It is located in an otherwise well-frequented part of Portland's downtown; the buildings on either side are commercial and house successful stores. But there's nothing in the alley... no detritus... no trash... no graffiti... nothing. Odd.