Honestly? The one thing I liked most about Istanbul were its cats (I admit, #catlady). They were everywhere and were also well taken care of. You would often find cat food on the streets, laid down for them by their human neighbours. Not one time did I see them get maltreated, but instead I saw Istanbul vendors petting the cats that were always near their market stall, or guiding the ones that were lost.
Here are some of my favourites.
PS. Feel like more? Check out Kedi, a documentary on the cats of Istanbul.