The soles or the bottom of the feet are called plantar surfaces and plantar warts are the tough, horny growths that develop on them. Because these areas are weight bearing and responsible for moving the human body from place to place, the warts that form on the plantar surfaces get forced into the skin which makes them particularly painful.Like all warts, they are harmless growths which will probably go away by themselves or with minimal treatment, but their location and the amount of pain invo.