Tomason

A , also spelled Thomason and Thomasson in English, is a kind of conceptual art or found art. Gempei Akasegawa created this word to describe certain kinds of useless parts of buildings or roads. These have lost their purpose as the environment around them changed. This kind of art is not made on purpose, but becomes art when people observe and recognize it.
Origin of the name.
Akasegawa named this special kind of "art" after an American baseball player who joined the Yomiuri Giants in 1981. Gary Thomasson became famous in Japan for getting the biggest baseball contract ever, then playing very poorly and retiring early.
Types of Tomason.
Tomason can be grouped by features they have in common. These include: "useless stairways", "pointless doorways", "overhangs", "blocked windows", "sealed up walls", "A-bomb type", (doors opening from a high place into open air), "outies", "poundcakes", "atago" (strange bumps or things sticking up out of the road for no reason), "premature burial" (when a wall is built partly covering an existing feature), and more.