I'm going to add smooth cobblestones to my list of favourites. Walking across the local market place is like getting a foot massage. Then walking onto the cool tiles of the indoor shopping centre on a hot day is a great feeling.
I like city streets, hot asphalt, subways, stores, and just about anywhere. I prefer tough, dirty feet. This is my clean sole:
I don't know I like to walk barefoot on every surface and feel them all I do love mud and grass, although the streets are nice on a hot day, I actually quite like when the tar melts and gets stuck to you soles, I don't know if thats just me but it think it feels fun. The feel is definitely one of the best reasons for being barefoot.
I can't seem to settle on a favorite surface to walk on. Like other people have indicated, I love being able to feel all the different things that I walk on. You definitely have more awareness of the world when you are barefoot..... even better when totally nude.
Hot asphalt! I prefer the smooth blacktop over the rougher and sharper rocky asphalt. Hot enough to burn with every step, hot enough to burn even when standing in asphalt shade. Hot enough that periodic walking to sidewalk is needed to cool the soles when even the asphalt shade is too hot. Sidewalk also more than challenging to stand on with the soles fully on the ground instead of rolling back and forth on them to distribute the burning to stand for a longer time.
There are so many...warm asphalt, hardwood floors, cool concrete like in a parking garage. Also love dirt trails and smooth linoleum floors.